[PATCH 0/2] Avoid passing global comment_line_char repeatedly

[PATCH 0/2] Avoid passing global comment_line_char repeatedly

[Junio C Hamano]

Two strbuf functions used to produce commented lines take the
comment_line_char as their parameter, but in practice, all callers
feed the global variable comment_line_char from environment.[ch].

Dropping the parameter from the callchain will make the interface
less flexible, and less error prone.  If we choose to change the
implementation of the customizable comment line character (e.g., we
may want to stop referencing the global variable and instead use a
getter function), we will have fewer places we need to modify.

Junio C Hamano (2):
  strbuf_commented_addf(): drop the comment_line_char parameter
  strbuf_add_commented_lines(): drop the comment_line_char parameter

 add-patch.c          |  8 ++++----
 builtin/branch.c     |  2 +-
 builtin/merge.c      |  8 ++++----
 builtin/notes.c      |  9 ++++-----
 builtin/stripspace.c |  2 +-
 builtin/tag.c        |  4 ++--
 fmt-merge-msg.c      |  9 +++------
 rebase-interactive.c |  8 ++++----
 sequencer.c          | 14 ++++++--------
 strbuf.c             |  9 +++++----
 strbuf.h             |  7 +++----
 wt-status.c          |  6 +++---
 12 files changed, 40 insertions(+), 46 deletions(-)

-- 
2.42.0-526-g3130c155df

[PATCH 1/2] strbuf_commented_addf(): drop the comment_line_char parameter

[Junio C Hamano]

All the callers of this function supply the global variable
comment_line_char as an argument to its second parameter.  Remove
the parameter to allow us in the future to change the reference to
the global variable with something else, like a function call.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 add-patch.c          | 8 ++++----
 builtin/branch.c     | 2 +-
 builtin/merge.c      | 8 ++++----
 builtin/tag.c        | 4 ++--
 rebase-interactive.c | 2 +-
 sequencer.c          | 4 ++--
 strbuf.c             | 3 ++-
 strbuf.h             | 4 ++--
 wt-status.c          | 2 +-
 9 files changed, 19 insertions(+), 18 deletions(-)

diff --git a/add-patch.c b/add-patch.c
index bfe19876cd..471a0037be 100644
--- a/add-patch.c
+++ b/add-patch.c
@@ -1106,11 +1106,11 @@ static int edit_hunk_manually(struct add_p_state *s, struct hunk *hunk)
 	size_t i;
 
 	strbuf_reset(&s->buf);
-	strbuf_commented_addf(&s->buf, comment_line_char,
+	strbuf_commented_addf(&s->buf,
 			      _("Manual hunk edit mode -- see bottom for "
 				"a quick guide.\n"));
 	render_hunk(s, hunk, 0, 0, &s->buf);
-	strbuf_commented_addf(&s->buf, comment_line_char,
+	strbuf_commented_addf(&s->buf,
 			      _("---\n"
 				"To remove '%c' lines, make them ' ' lines "
 				"(context).\n"
@@ -1119,13 +1119,13 @@ static int edit_hunk_manually(struct add_p_state *s, struct hunk *hunk)
 			      s->mode->is_reverse ? '+' : '-',
 			      s->mode->is_reverse ? '-' : '+',
 			      comment_line_char);
-	strbuf_commented_addf(&s->buf, comment_line_char, "%s",
+	strbuf_commented_addf(&s->buf, "%s",
 			      _(s->mode->edit_hunk_hint));
 	/*
 	 * TRANSLATORS: 'it' refers to the patch mentioned in the previous
 	 * messages.
 	 */
-	strbuf_commented_addf(&s->buf, comment_line_char,
+	strbuf_commented_addf(&s->buf,
 			      _("If it does not apply cleanly, you will be "
 				"given an opportunity to\n"
 				"edit again.  If all lines of the hunk are "
diff --git a/builtin/branch.c b/builtin/branch.c
index 2ec190b14a..b2f171e10b 100644
--- a/builtin/branch.c
+++ b/builtin/branch.c
@@ -668,7 +668,7 @@ static int edit_branch_description(const char *branch_name)
 	exists = !read_branch_desc(&buf, branch_name);
 	if (!buf.len || buf.buf[buf.len-1] != '\n')
 		strbuf_addch(&buf, '\n');
-	strbuf_commented_addf(&buf, comment_line_char,
+	strbuf_commented_addf(&buf,
 		    _("Please edit the description for the branch\n"
 		      "  %s\n"
 		      "Lines starting with '%c' will be stripped.\n"),
diff --git a/builtin/merge.c b/builtin/merge.c
index d748d46e13..8f0e8be7c3 100644
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -857,15 +857,15 @@ static void prepare_to_commit(struct commit_list *remoteheads)
 		strbuf_addch(&msg, '\n');
 		if (cleanup_mode == COMMIT_MSG_CLEANUP_SCISSORS) {
 			wt_status_append_cut_line(&msg);
-			strbuf_commented_addf(&msg, comment_line_char, "\n");
+			strbuf_commented_addf(&msg, "\n");
 		}
-		strbuf_commented_addf(&msg, comment_line_char,
+		strbuf_commented_addf(&msg,
 				      _(merge_editor_comment));
 		if (cleanup_mode == COMMIT_MSG_CLEANUP_SCISSORS)
-			strbuf_commented_addf(&msg, comment_line_char,
+			strbuf_commented_addf(&msg,
 					      _(scissors_editor_comment));
 		else
-			strbuf_commented_addf(&msg, comment_line_char,
+			strbuf_commented_addf(&msg,
 				_(no_scissors_editor_comment), comment_line_char);
 	}
 	if (signoff)
diff --git a/builtin/tag.c b/builtin/tag.c
index 3918eacbb5..a85a0d8def 100644
--- a/builtin/tag.c
+++ b/builtin/tag.c
@@ -314,10 +314,10 @@ static void create_tag(const struct object_id *object, const char *object_ref,
 			struct strbuf buf = STRBUF_INIT;
 			strbuf_addch(&buf, '\n');
 			if (opt->cleanup_mode == CLEANUP_ALL)
-				strbuf_commented_addf(&buf, comment_line_char,
+				strbuf_commented_addf(&buf,
 				      _(tag_template), tag, comment_line_char);
 			else
-				strbuf_commented_addf(&buf, comment_line_char,
+				strbuf_commented_addf(&buf,
 				      _(tag_template_nocleanup), tag, comment_line_char);
 			write_or_die(fd, buf.buf, buf.len);
 			strbuf_release(&buf);
diff --git a/rebase-interactive.c b/rebase-interactive.c
index d9718409b3..3f33da7f03 100644
--- a/rebase-interactive.c
+++ b/rebase-interactive.c
@@ -71,7 +71,7 @@ void append_todo_help(int command_count,
 
 	if (!edit_todo) {
 		strbuf_addch(buf, '\n');
-		strbuf_commented_addf(buf, comment_line_char,
+		strbuf_commented_addf(buf,
 				      Q_("Rebase %s onto %s (%d command)",
 					 "Rebase %s onto %s (%d commands)",
 					 command_count),
diff --git a/sequencer.c b/sequencer.c
index d584cac8ed..5d348a3f12 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -675,11 +675,11 @@ void append_conflicts_hint(struct index_state *istate,
 	}
 
 	strbuf_addch(msgbuf, '\n');
-	strbuf_commented_addf(msgbuf, comment_line_char, "Conflicts:\n");
+	strbuf_commented_addf(msgbuf, "Conflicts:\n");
 	for (i = 0; i < istate->cache_nr;) {
 		const struct cache_entry *ce = istate->cache[i++];
 		if (ce_stage(ce)) {
-			strbuf_commented_addf(msgbuf, comment_line_char,
+			strbuf_commented_addf(msgbuf,
 					      "\t%s\n", ce->name);
 			while (i < istate->cache_nr &&
 			       !strcmp(ce->name, istate->cache[i]->name))
diff --git a/strbuf.c b/strbuf.c
index 7827178d8e..15550b2619 100644
--- a/strbuf.c
+++ b/strbuf.c
@@ -1,4 +1,5 @@
 #include "git-compat-util.h"
+#include "environment.h"
 #include "gettext.h"
 #include "hex-ll.h"
 #include "strbuf.h"
@@ -372,7 +373,7 @@ void strbuf_add_commented_lines(struct strbuf *out, const char *buf,
 	add_lines(out, prefix1, prefix2, buf, size);
 }
 
-void strbuf_commented_addf(struct strbuf *sb, char comment_line_char,
+void strbuf_commented_addf(struct strbuf *sb,
 			   const char *fmt, ...)
 {
 	va_list params;
diff --git a/strbuf.h b/strbuf.h
index e959caca87..981617dc77 100644
--- a/strbuf.h
+++ b/strbuf.h
@@ -378,8 +378,8 @@ void strbuf_addf(struct strbuf *sb, const char *fmt, ...);
  * Add a formatted string prepended by a comment character and a
  * blank to the buffer.
  */
-__attribute__((format (printf, 3, 4)))
-void strbuf_commented_addf(struct strbuf *sb, char comment_line_char, const char *fmt, ...);
+__attribute__((format (printf, 2, 3)))
+void strbuf_commented_addf(struct strbuf *sb, const char *fmt, ...);
 
 __attribute__((format (printf,2,0)))
 void strbuf_vaddf(struct strbuf *sb, const char *fmt, va_list ap);
diff --git a/wt-status.c b/wt-status.c
index 9f45bf6949..54b2775730 100644
--- a/wt-status.c
+++ b/wt-status.c
@@ -1102,7 +1102,7 @@ void wt_status_append_cut_line(struct strbuf *buf)
 {
 	const char *explanation = _("Do not modify or remove the line above.\nEverything below it will be ignored.");
 
-	strbuf_commented_addf(buf, comment_line_char, "%s", cut_line);
+	strbuf_commented_addf(buf, "%s", cut_line);
 	strbuf_add_commented_lines(buf, explanation, strlen(explanation), comment_line_char);
 }
 
-- 
2.42.0-526-g3130c155df

[PATCH 2/2] strbuf_add_commented_lines(): drop the comment_line_char parameter

[Junio C Hamano]

All the callers of this function supply the global variable
comment_line_char as an argument to its last parameter.  Remove the
parameter to allow us in the future to change the reference to the
global variable with something else, like a function call.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 builtin/notes.c      |  9 ++++-----
 builtin/stripspace.c |  2 +-
 fmt-merge-msg.c      |  9 +++------
 rebase-interactive.c |  6 +++---
 sequencer.c          | 10 ++++------
 strbuf.c             |  6 +++---
 strbuf.h             |  3 +--
 wt-status.c          |  4 ++--
 8 files changed, 21 insertions(+), 28 deletions(-)

diff --git a/builtin/notes.c b/builtin/notes.c
index 9f38863dd5..355ecce07a 100644
--- a/builtin/notes.c
+++ b/builtin/notes.c
@@ -181,7 +181,7 @@ static void write_commented_object(int fd, const struct object_id *object)
 
 	if (strbuf_read(&buf, show.out, 0) < 0)
 		die_errno(_("could not read 'show' output"));
-	strbuf_add_commented_lines(&cbuf, buf.buf, buf.len, comment_line_char);
+	strbuf_add_commented_lines(&cbuf, buf.buf, buf.len);
 	write_or_die(fd, cbuf.buf, cbuf.len);
 
 	strbuf_release(&cbuf);
@@ -209,10 +209,9 @@ static void prepare_note_data(const struct object_id *object, struct note_data *
 			copy_obj_to_fd(fd, old_note);
 
 		strbuf_addch(&buf, '\n');
-		strbuf_add_commented_lines(&buf, "\n", strlen("\n"), comment_line_char);
-		strbuf_add_commented_lines(&buf, _(note_template), strlen(_(note_template)),
-					   comment_line_char);
-		strbuf_add_commented_lines(&buf, "\n", strlen("\n"), comment_line_char);
+		strbuf_add_commented_lines(&buf, "\n", strlen("\n"));
+		strbuf_add_commented_lines(&buf, _(note_template), strlen(_(note_template)));
+		strbuf_add_commented_lines(&buf, "\n", strlen("\n"));
 		write_or_die(fd, buf.buf, buf.len);
 
 		write_commented_object(fd, object);
diff --git a/builtin/stripspace.c b/builtin/stripspace.c
index 7b700a9fb1..11e475760c 100644
--- a/builtin/stripspace.c
+++ b/builtin/stripspace.c
@@ -13,7 +13,7 @@ static void comment_lines(struct strbuf *buf)
 	size_t len;
 
 	msg = strbuf_detach(buf, &len);
-	strbuf_add_commented_lines(buf, msg, len, comment_line_char);
+	strbuf_add_commented_lines(buf, msg, len);
 	free(msg);
 }
 
diff --git a/fmt-merge-msg.c b/fmt-merge-msg.c
index 66e47449a0..adc85d2a72 100644
--- a/fmt-merge-msg.c
+++ b/fmt-merge-msg.c
@@ -509,8 +509,7 @@ static void fmt_tag_signature(struct strbuf *tagbuf,
 	strbuf_complete_line(tagbuf);
 	if (sig->len) {
 		strbuf_addch(tagbuf, '\n');
-		strbuf_add_commented_lines(tagbuf, sig->buf, sig->len,
-					   comment_line_char);
+		strbuf_add_commented_lines(tagbuf, sig->buf, sig->len);
 	}
 }
 
@@ -556,8 +555,7 @@ static void fmt_merge_msg_sigs(struct strbuf *out)
 				strbuf_addch(&tagline, '\n');
 				strbuf_add_commented_lines(&tagline,
 						origins.items[first_tag].string,
-						strlen(origins.items[first_tag].string),
-						comment_line_char);
+						strlen(origins.items[first_tag].string));
 				strbuf_insert(&tagbuf, 0, tagline.buf,
 					      tagline.len);
 				strbuf_release(&tagline);
@@ -565,8 +563,7 @@ static void fmt_merge_msg_sigs(struct strbuf *out)
 			strbuf_addch(&tagbuf, '\n');
 			strbuf_add_commented_lines(&tagbuf,
 					origins.items[i].string,
-					strlen(origins.items[i].string),
-					comment_line_char);
+					strlen(origins.items[i].string));
 			fmt_tag_signature(&tagbuf, &sig, buf, len);
 		}
 		strbuf_release(&payload);
diff --git a/rebase-interactive.c b/rebase-interactive.c
index 3f33da7f03..1138bd37ba 100644
--- a/rebase-interactive.c
+++ b/rebase-interactive.c
@@ -78,7 +78,7 @@ void append_todo_help(int command_count,
 				      shortrevisions, shortonto, command_count);
 	}
 
-	strbuf_add_commented_lines(buf, msg, strlen(msg), comment_line_char);
+	strbuf_add_commented_lines(buf, msg, strlen(msg));
 
 	if (get_missing_commit_check_level() == MISSING_COMMIT_CHECK_ERROR)
 		msg = _("\nDo not remove any line. Use 'drop' "
@@ -87,7 +87,7 @@ void append_todo_help(int command_count,
 		msg = _("\nIf you remove a line here "
 			 "THAT COMMIT WILL BE LOST.\n");
 
-	strbuf_add_commented_lines(buf, msg, strlen(msg), comment_line_char);
+	strbuf_add_commented_lines(buf, msg, strlen(msg));
 
 	if (edit_todo)
 		msg = _("\nYou are editing the todo file "
@@ -98,7 +98,7 @@ void append_todo_help(int command_count,
 		msg = _("\nHowever, if you remove everything, "
 			"the rebase will be aborted.\n\n");
 
-	strbuf_add_commented_lines(buf, msg, strlen(msg), comment_line_char);
+	strbuf_add_commented_lines(buf, msg, strlen(msg));
 }
 
 int edit_todo_list(struct repository *r, struct todo_list *todo_list,
diff --git a/sequencer.c b/sequencer.c
index 5d348a3f12..29c8b5e32b 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -1859,7 +1859,7 @@ static void add_commented_lines(struct strbuf *buf, const void *str, size_t len)
 		s += count;
 		len -= count;
 	}
-	strbuf_add_commented_lines(buf, s, len, comment_line_char);
+	strbuf_add_commented_lines(buf, s, len);
 }
 
 /* Does the current fixup chain contain a squash command? */
@@ -1958,7 +1958,7 @@ static int append_squash_message(struct strbuf *buf, const char *body,
 	strbuf_addf(buf, _(nth_commit_msg_fmt),
 		    ++opts->current_fixup_count + 1);
 	strbuf_addstr(buf, "\n\n");
-	strbuf_add_commented_lines(buf, body, commented_len, comment_line_char);
+	strbuf_add_commented_lines(buf, body, commented_len);
 	/* buf->buf may be reallocated so store an offset into the buffer */
 	fixup_off = buf->len;
 	strbuf_addstr(buf, body + commented_len);
@@ -2048,8 +2048,7 @@ static int update_squash_messages(struct repository *r,
 			      _(first_commit_msg_str));
 		strbuf_addstr(&buf, "\n\n");
 		if (is_fixup_flag(command, flag))
-			strbuf_add_commented_lines(&buf, body, strlen(body),
-						   comment_line_char);
+			strbuf_add_commented_lines(&buf, body, strlen(body));
 		else
 			strbuf_addstr(&buf, body);
 
@@ -2068,8 +2067,7 @@ static int update_squash_messages(struct repository *r,
 		strbuf_addf(&buf, _(skip_nth_commit_msg_fmt),
 			    ++opts->current_fixup_count + 1);
 		strbuf_addstr(&buf, "\n\n");
-		strbuf_add_commented_lines(&buf, body, strlen(body),
-					   comment_line_char);
+		strbuf_add_commented_lines(&buf, body, strlen(body));
 	} else
 		return error(_("unknown command: %d"), command);
 	repo_unuse_commit_buffer(r, commit, message);
diff --git a/strbuf.c b/strbuf.c
index 15550b2619..2088f7800a 100644
--- a/strbuf.c
+++ b/strbuf.c
@@ -360,8 +360,8 @@ static void add_lines(struct strbuf *out,
 	strbuf_complete_line(out);
 }
 
-void strbuf_add_commented_lines(struct strbuf *out, const char *buf,
-				size_t size, char comment_line_char)
+void strbuf_add_commented_lines(struct strbuf *out,
+				const char *buf, size_t size)
 {
 	static char prefix1[3];
 	static char prefix2[2];
@@ -384,7 +384,7 @@ void strbuf_commented_addf(struct strbuf *sb,
 	strbuf_vaddf(&buf, fmt, params);
 	va_end(params);
 
-	strbuf_add_commented_lines(sb, buf.buf, buf.len, comment_line_char);
+	strbuf_add_commented_lines(sb, buf.buf, buf.len);
 	if (incomplete_line)
 		sb->buf[--sb->len] = '\0';
 
diff --git a/strbuf.h b/strbuf.h
index 981617dc77..4547efa62e 100644
--- a/strbuf.h
+++ b/strbuf.h
@@ -287,8 +287,7 @@ void strbuf_splice(struct strbuf *sb, size_t pos, size_t len,
  * by a comment character and a blank.
  */
 void strbuf_add_commented_lines(struct strbuf *out,
-				const char *buf, size_t size,
-				char comment_line_char);
+				const char *buf, size_t size);
 
 
 /**
diff --git a/wt-status.c b/wt-status.c
index 54b2775730..b390c77334 100644
--- a/wt-status.c
+++ b/wt-status.c
@@ -1027,7 +1027,7 @@ static void wt_longstatus_print_submodule_summary(struct wt_status *s, int uncom
 	if (s->display_comment_prefix) {
 		size_t len;
 		summary_content = strbuf_detach(&summary, &len);
-		strbuf_add_commented_lines(&summary, summary_content, len, comment_line_char);
+		strbuf_add_commented_lines(&summary, summary_content, len);
 		free(summary_content);
 	}
 
@@ -1103,7 +1103,7 @@ void wt_status_append_cut_line(struct strbuf *buf)
 	const char *explanation = _("Do not modify or remove the line above.\nEverything below it will be ignored.");
 
 	strbuf_commented_addf(buf, "%s", cut_line);
-	strbuf_add_commented_lines(buf, explanation, strlen(explanation), comment_line_char);
+	strbuf_add_commented_lines(buf, explanation, strlen(explanation));
 }
 
 void wt_status_add_cut_line(FILE *fp)
-- 
2.42.0-526-g3130c155df

Re: [PATCH 0/2] Avoid passing global comment_line_char repeatedly

[Dragan Simic]

On 2023-10-30 06:10, Junio C Hamano wrote:
> Two strbuf functions used to produce commented lines take the
> comment_line_char as their parameter, but in practice, all callers
> feed the global variable comment_line_char from environment.[ch].
> 
> Dropping the parameter from the callchain will make the interface
> less flexible, and less error prone.  If we choose to change the
> implementation of the customizable comment line character (e.g., we
> may want to stop referencing the global variable and instead use a
> getter function), we will have fewer places we need to modify.
> 
> Junio C Hamano (2):
>   strbuf_commented_addf(): drop the comment_line_char parameter
>   strbuf_add_commented_lines(): drop the comment_line_char parameter

This series looks good to me.  It removes unnecessary complexity that 
provided pretty much no value.

>  add-patch.c          |  8 ++++----
>  builtin/branch.c     |  2 +-
>  builtin/merge.c      |  8 ++++----
>  builtin/notes.c      |  9 ++++-----
>  builtin/stripspace.c |  2 +-
>  builtin/tag.c        |  4 ++--
>  fmt-merge-msg.c      |  9 +++------
>  rebase-interactive.c |  8 ++++----
>  sequencer.c          | 14 ++++++--------
>  strbuf.c             |  9 +++++----
>  strbuf.h             |  7 +++----
>  wt-status.c          |  6 +++---
>  12 files changed, 40 insertions(+), 46 deletions(-)

Re: [PATCH 0/2] Avoid passing global comment_line_char repeatedly

[Phillip Wood]

Hi Junio

On 30/10/2023 05:10, Junio C Hamano wrote:
> Two strbuf functions used to produce commented lines take the
> comment_line_char as their parameter, but in practice, all callers
> feed the global variable comment_line_char from environment.[ch].
> 
> Dropping the parameter from the callchain will make the interface
> less flexible, and less error prone.  If we choose to change the
> implementation of the customizable comment line character (e.g., we
> may want to stop referencing the global variable and instead use a
> getter function), we will have fewer places we need to modify.

While I agree with your reasoning here, I think that parameter was 
recently added as part of the libification effort - I can't remember 
exactly why and am too lazy to look it up so I've cc'd Calvin and 
Johathan instead.

Best Wishes

Phillip

> Junio C Hamano (2):
>    strbuf_commented_addf(): drop the comment_line_char parameter
>    strbuf_add_commented_lines(): drop the comment_line_char parameter
> 
>   add-patch.c          |  8 ++++----
>   builtin/branch.c     |  2 +-
>   builtin/merge.c      |  8 ++++----
>   builtin/notes.c      |  9 ++++-----
>   builtin/stripspace.c |  2 +-
>   builtin/tag.c        |  4 ++--
>   fmt-merge-msg.c      |  9 +++------
>   rebase-interactive.c |  8 ++++----
>   sequencer.c          | 14 ++++++--------
>   strbuf.c             |  9 +++++----
>   strbuf.h             |  7 +++----
>   wt-status.c          |  6 +++---
>   12 files changed, 40 insertions(+), 46 deletions(-)
> 

[RFC PATCH 0/3] Avoid passing global comment_line_char repeatedly

[Jonathan Tan]

> While I agree with your reasoning here, I think that parameter was 
> recently added as part of the libification effort - I can't remember 
> exactly why and am too lazy to look it up so I've cc'd Calvin and 
> Johathan instead.

Thanks Phillip for noticing this. Putting on my libification hat,
this was probably because we wanted to remove strbuf's dependency on
environment, so that we wouldn't need to include it in git-std-lib. If
we were to merge these patches, libification would probably still be
doable if we stubbed the global comment_line_char.

Removing my libification hat, I think it's better to solve this issue
by moving the functions into environment.{c,h} instead, following
the example of functions like strbuf_worktree_ref() in worktree.h
and strbuf_utf8_align() in utf8.h that, when operating on both strbuf
and a specific domain, are placed in the domain's header file, not in
strbuf.h. This avoids a situation in which strbuf.h contains everything
string-related.

The main issue with this is that by not centralizing all strbuf-related
functionality, some strbuf-related helper functions that could have been
private now need to be made public, but I think that a similar issue
would be faced if we don't centralize, say, all environment-related
functionality (some environment-related helper functions would have to
be made public, although I didn't encounter this problem with this patch
set).

I've attached some patches to illustrate what I've described above.

Jonathan Tan (1):
  strbuf: make add_lines() public

Junio C Hamano (2):
  strbuf_commented_addf(): drop the comment_line_char parameter
  strbuf_add_commented_lines(): drop the comment_line_char parameter

 add-patch.c          |  8 ++---
 branch.c             |  3 +-
 builtin/branch.c     |  2 +-
 builtin/merge.c      |  8 ++---
 builtin/notes.c      |  9 +++---
 builtin/stripspace.c |  2 +-
 builtin/tag.c        |  4 +--
 commit.c             |  2 +-
 environment.c        | 31 ++++++++++++++++++++
 environment.h        | 14 +++++++++
 fmt-merge-msg.c      |  9 ++----
 rebase-interactive.c |  8 ++---
 sequencer.c          | 14 ++++-----
 strbuf.c             | 69 ++++++++++----------------------------------
 strbuf.h             | 19 ++----------
 wt-status.c          |  6 ++--
 16 files changed, 98 insertions(+), 110 deletions(-)

-- 
2.42.0.820.g83a721a137-goog

[RFC PATCH 1/3] strbuf: make add_lines() public

[Jonathan Tan]

Subsequent patches will require the ability to add different prefixes
to different lines (depending on their contents), so make this
functionality available from outside strbuf.c.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
---
 branch.c |  3 ++-
 commit.c |  2 +-
 strbuf.c | 39 ++++++++++++++++-----------------------
 strbuf.h |  3 ++-
 4 files changed, 21 insertions(+), 26 deletions(-)

diff --git a/branch.c b/branch.c
index 06f7af9dd4..04a8b90b6a 100644
--- a/branch.c
+++ b/branch.c
@@ -721,7 +721,8 @@ static int submodule_create_branch(struct repository *r,
 		return ret;
 	ret = finish_command(&child);
 	strbuf_read(&child_err, child.err, 0);
-	strbuf_add_lines(&out_buf, out_prefix, child_err.buf, child_err.len);
+	strbuf_add_lines(&out_buf, out_prefix, out_prefix,
+			 child_err.buf, child_err.len);
 
 	if (ret)
 		fprintf(stderr, "%s", out_buf.buf);
diff --git a/commit.c b/commit.c
index b3223478bc..7caafcde01 100644
--- a/commit.c
+++ b/commit.c
@@ -1361,7 +1361,7 @@ static void add_extra_header(struct strbuf *buffer,
 {
 	strbuf_addstr(buffer, extra->key);
 	if (extra->len)
-		strbuf_add_lines(buffer, " ", extra->value, extra->len);
+		strbuf_add_lines(buffer, " ", " ", extra->value, extra->len);
 	else
 		strbuf_addch(buffer, '\n');
 }
diff --git a/strbuf.c b/strbuf.c
index 7827178d8e..9ee639519a 100644
--- a/strbuf.c
+++ b/strbuf.c
@@ -339,26 +339,6 @@ void strbuf_addf(struct strbuf *sb, const char *fmt, ...)
 	va_end(ap);
 }
 
-static void add_lines(struct strbuf *out,
-			const char *prefix1,
-			const char *prefix2,
-			const char *buf, size_t size)
-{
-	while (size) {
-		const char *prefix;
-		const char *next = memchr(buf, '\n', size);
-		next = next ? (next + 1) : (buf + size);
-
-		prefix = ((prefix2 && (buf[0] == '\n' || buf[0] == '\t'))
-			  ? prefix2 : prefix1);
-		strbuf_addstr(out, prefix);
-		strbuf_add(out, buf, next - buf);
-		size -= next - buf;
-		buf = next;
-	}
-	strbuf_complete_line(out);
-}
-
 void strbuf_add_commented_lines(struct strbuf *out, const char *buf,
 				size_t size, char comment_line_char)
 {
@@ -369,7 +349,7 @@ void strbuf_add_commented_lines(struct strbuf *out, const char *buf,
 		xsnprintf(prefix1, sizeof(prefix1), "%c ", comment_line_char);
 		xsnprintf(prefix2, sizeof(prefix2), "%c", comment_line_char);
 	}
-	add_lines(out, prefix1, prefix2, buf, size);
+	strbuf_add_lines(out, prefix1, prefix2, buf, size);
 }
 
 void strbuf_commented_addf(struct strbuf *sb, char comment_line_char,
@@ -747,10 +727,23 @@ ssize_t strbuf_read_file(struct strbuf *sb, const char *path, size_t hint)
 	return len;
 }
 
-void strbuf_add_lines(struct strbuf *out, const char *prefix,
+void strbuf_add_lines(struct strbuf *out, const char *default_prefix,
+		      const char *tab_or_nl_prefix,
 		      const char *buf, size_t size)
 {
-	add_lines(out, prefix, NULL, buf, size);
+	while (size) {
+		const char *prefix;
+		const char *next = memchr(buf, '\n', size);
+		next = next ? (next + 1) : (buf + size);
+
+		prefix = (buf[0] == '\n' || buf[0] == '\t')
+			  ? tab_or_nl_prefix : default_prefix;
+		strbuf_addstr(out, prefix);
+		strbuf_add(out, buf, next - buf);
+		size -= next - buf;
+		buf = next;
+	}
+	strbuf_complete_line(out);
 }
 
 void strbuf_addstr_xml_quoted(struct strbuf *buf, const char *s)
diff --git a/strbuf.h b/strbuf.h
index e959caca87..3559e73dd8 100644
--- a/strbuf.h
+++ b/strbuf.h
@@ -599,7 +599,8 @@ void strbuf_list_free(struct strbuf **list);
 void strbuf_strip_file_from_path(struct strbuf *sb);
 
 void strbuf_add_lines(struct strbuf *sb,
-		      const char *prefix,
+		      const char *default_prefix,
+		      const char *tab_or_nl_prefix,
 		      const char *buf,
 		      size_t size);
 
-- 
2.42.0.820.g83a721a137-goog

[RFC PATCH 2/3] strbuf_commented_addf(): drop the comment_line_char parameter

[Jonathan Tan]

From: Junio C Hamano <gitster@pobox.com>

All the callers of this function supply the global variable
comment_line_char as an argument to its second parameter.  Remove
the parameter to allow us in the future to change the reference to
the global variable with something else, like a function call.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
---
 add-patch.c          |  8 ++++----
 builtin/branch.c     |  2 +-
 builtin/merge.c      |  8 ++++----
 builtin/tag.c        |  4 ++--
 environment.c        | 18 ++++++++++++++++++
 environment.h        |  7 +++++++
 rebase-interactive.c |  2 +-
 sequencer.c          |  4 ++--
 strbuf.c             | 19 +------------------
 strbuf.h             |  7 -------
 wt-status.c          |  2 +-
 11 files changed, 41 insertions(+), 40 deletions(-)

diff --git a/add-patch.c b/add-patch.c
index bfe19876cd..471a0037be 100644
--- a/add-patch.c
+++ b/add-patch.c
@@ -1106,11 +1106,11 @@ static int edit_hunk_manually(struct add_p_state *s, struct hunk *hunk)
 	size_t i;
 
 	strbuf_reset(&s->buf);
-	strbuf_commented_addf(&s->buf, comment_line_char,
+	strbuf_commented_addf(&s->buf,
 			      _("Manual hunk edit mode -- see bottom for "
 				"a quick guide.\n"));
 	render_hunk(s, hunk, 0, 0, &s->buf);
-	strbuf_commented_addf(&s->buf, comment_line_char,
+	strbuf_commented_addf(&s->buf,
 			      _("---\n"
 				"To remove '%c' lines, make them ' ' lines "
 				"(context).\n"
@@ -1119,13 +1119,13 @@ static int edit_hunk_manually(struct add_p_state *s, struct hunk *hunk)
 			      s->mode->is_reverse ? '+' : '-',
 			      s->mode->is_reverse ? '-' : '+',
 			      comment_line_char);
-	strbuf_commented_addf(&s->buf, comment_line_char, "%s",
+	strbuf_commented_addf(&s->buf, "%s",
 			      _(s->mode->edit_hunk_hint));
 	/*
 	 * TRANSLATORS: 'it' refers to the patch mentioned in the previous
 	 * messages.
 	 */
-	strbuf_commented_addf(&s->buf, comment_line_char,
+	strbuf_commented_addf(&s->buf,
 			      _("If it does not apply cleanly, you will be "
 				"given an opportunity to\n"
 				"edit again.  If all lines of the hunk are "
diff --git a/builtin/branch.c b/builtin/branch.c
index 2ec190b14a..b2f171e10b 100644
--- a/builtin/branch.c
+++ b/builtin/branch.c
@@ -668,7 +668,7 @@ static int edit_branch_description(const char *branch_name)
 	exists = !read_branch_desc(&buf, branch_name);
 	if (!buf.len || buf.buf[buf.len-1] != '\n')
 		strbuf_addch(&buf, '\n');
-	strbuf_commented_addf(&buf, comment_line_char,
+	strbuf_commented_addf(&buf,
 		    _("Please edit the description for the branch\n"
 		      "  %s\n"
 		      "Lines starting with '%c' will be stripped.\n"),
diff --git a/builtin/merge.c b/builtin/merge.c
index d748d46e13..8f0e8be7c3 100644
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -857,15 +857,15 @@ static void prepare_to_commit(struct commit_list *remoteheads)
 		strbuf_addch(&msg, '\n');
 		if (cleanup_mode == COMMIT_MSG_CLEANUP_SCISSORS) {
 			wt_status_append_cut_line(&msg);
-			strbuf_commented_addf(&msg, comment_line_char, "\n");
+			strbuf_commented_addf(&msg, "\n");
 		}
-		strbuf_commented_addf(&msg, comment_line_char,
+		strbuf_commented_addf(&msg,
 				      _(merge_editor_comment));
 		if (cleanup_mode == COMMIT_MSG_CLEANUP_SCISSORS)
-			strbuf_commented_addf(&msg, comment_line_char,
+			strbuf_commented_addf(&msg,
 					      _(scissors_editor_comment));
 		else
-			strbuf_commented_addf(&msg, comment_line_char,
+			strbuf_commented_addf(&msg,
 				_(no_scissors_editor_comment), comment_line_char);
 	}
 	if (signoff)
diff --git a/builtin/tag.c b/builtin/tag.c
index 3918eacbb5..a85a0d8def 100644
--- a/builtin/tag.c
+++ b/builtin/tag.c
@@ -314,10 +314,10 @@ static void create_tag(const struct object_id *object, const char *object_ref,
 			struct strbuf buf = STRBUF_INIT;
 			strbuf_addch(&buf, '\n');
 			if (opt->cleanup_mode == CLEANUP_ALL)
-				strbuf_commented_addf(&buf, comment_line_char,
+				strbuf_commented_addf(&buf,
 				      _(tag_template), tag, comment_line_char);
 			else
-				strbuf_commented_addf(&buf, comment_line_char,
+				strbuf_commented_addf(&buf,
 				      _(tag_template_nocleanup), tag, comment_line_char);
 			write_or_die(fd, buf.buf, buf.len);
 			strbuf_release(&buf);
diff --git a/environment.c b/environment.c
index bb3c2a96a3..d9f64cffa0 100644
--- a/environment.c
+++ b/environment.c
@@ -416,3 +416,21 @@ int print_sha1_ellipsis(void)
 	}
 	return cached_result;
 }
+
+void strbuf_commented_addf(struct strbuf *sb,
+			   const char *fmt, ...)
+{
+	va_list params;
+	struct strbuf buf = STRBUF_INIT;
+	int incomplete_line = sb->len && sb->buf[sb->len - 1] != '\n';
+
+	va_start(params, fmt);
+	strbuf_vaddf(&buf, fmt, params);
+	va_end(params);
+
+	strbuf_add_commented_lines(sb, buf.buf, buf.len, comment_line_char);
+	if (incomplete_line)
+		sb->buf[--sb->len] = '\0';
+
+	strbuf_release(&buf);
+}
diff --git a/environment.h b/environment.h
index e5351c9dd9..5778f5a8e4 100644
--- a/environment.h
+++ b/environment.h
@@ -229,4 +229,11 @@ extern const char *excludes_file;
  */
 int print_sha1_ellipsis(void);
 
+/**
+ * Add a formatted string prepended by a comment character and a
+ * blank to the buffer.
+ */
+__attribute__((format (printf, 2, 3)))
+void strbuf_commented_addf(struct strbuf *sb, const char *fmt, ...);
+
 #endif
diff --git a/rebase-interactive.c b/rebase-interactive.c
index d9718409b3..3f33da7f03 100644
--- a/rebase-interactive.c
+++ b/rebase-interactive.c
@@ -71,7 +71,7 @@ void append_todo_help(int command_count,
 
 	if (!edit_todo) {
 		strbuf_addch(buf, '\n');
-		strbuf_commented_addf(buf, comment_line_char,
+		strbuf_commented_addf(buf,
 				      Q_("Rebase %s onto %s (%d command)",
 					 "Rebase %s onto %s (%d commands)",
 					 command_count),
diff --git a/sequencer.c b/sequencer.c
index d584cac8ed..5d348a3f12 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -675,11 +675,11 @@ void append_conflicts_hint(struct index_state *istate,
 	}
 
 	strbuf_addch(msgbuf, '\n');
-	strbuf_commented_addf(msgbuf, comment_line_char, "Conflicts:\n");
+	strbuf_commented_addf(msgbuf, "Conflicts:\n");
 	for (i = 0; i < istate->cache_nr;) {
 		const struct cache_entry *ce = istate->cache[i++];
 		if (ce_stage(ce)) {
-			strbuf_commented_addf(msgbuf, comment_line_char,
+			strbuf_commented_addf(msgbuf,
 					      "\t%s\n", ce->name);
 			while (i < istate->cache_nr &&
 			       !strcmp(ce->name, istate->cache[i]->name))
diff --git a/strbuf.c b/strbuf.c
index 9ee639519a..b1717270a2 100644
--- a/strbuf.c
+++ b/strbuf.c
@@ -1,4 +1,5 @@
 #include "git-compat-util.h"
+#include "environment.h"
 #include "gettext.h"
 #include "hex-ll.h"
 #include "strbuf.h"
@@ -352,24 +353,6 @@ void strbuf_add_commented_lines(struct strbuf *out, const char *buf,
 	strbuf_add_lines(out, prefix1, prefix2, buf, size);
 }
 
-void strbuf_commented_addf(struct strbuf *sb, char comment_line_char,
-			   const char *fmt, ...)
-{
-	va_list params;
-	struct strbuf buf = STRBUF_INIT;
-	int incomplete_line = sb->len && sb->buf[sb->len - 1] != '\n';
-
-	va_start(params, fmt);
-	strbuf_vaddf(&buf, fmt, params);
-	va_end(params);
-
-	strbuf_add_commented_lines(sb, buf.buf, buf.len, comment_line_char);
-	if (incomplete_line)
-		sb->buf[--sb->len] = '\0';
-
-	strbuf_release(&buf);
-}
-
 void strbuf_vaddf(struct strbuf *sb, const char *fmt, va_list ap)
 {
 	int len;
diff --git a/strbuf.h b/strbuf.h
index 3559e73dd8..4c58dc25e9 100644
--- a/strbuf.h
+++ b/strbuf.h
@@ -374,13 +374,6 @@ void strbuf_humanise_rate(struct strbuf *buf, off_t bytes);
 __attribute__((format (printf,2,3)))
 void strbuf_addf(struct strbuf *sb, const char *fmt, ...);
 
-/**
- * Add a formatted string prepended by a comment character and a
- * blank to the buffer.
- */
-__attribute__((format (printf, 3, 4)))
-void strbuf_commented_addf(struct strbuf *sb, char comment_line_char, const char *fmt, ...);
-
 __attribute__((format (printf,2,0)))
 void strbuf_vaddf(struct strbuf *sb, const char *fmt, va_list ap);
 
diff --git a/wt-status.c b/wt-status.c
index 9f45bf6949..54b2775730 100644
--- a/wt-status.c
+++ b/wt-status.c
@@ -1102,7 +1102,7 @@ void wt_status_append_cut_line(struct strbuf *buf)
 {
 	const char *explanation = _("Do not modify or remove the line above.\nEverything below it will be ignored.");
 
-	strbuf_commented_addf(buf, comment_line_char, "%s", cut_line);
+	strbuf_commented_addf(buf, "%s", cut_line);
 	strbuf_add_commented_lines(buf, explanation, strlen(explanation), comment_line_char);
 }
 
-- 
2.42.0.820.g83a721a137-goog

[RFC PATCH 3/3] strbuf_add_commented_lines(): drop the comment_line_char parameter

[Jonathan Tan]

From: Junio C Hamano <gitster@pobox.com>

All the callers of this function supply the global variable
comment_line_char as an argument to its last parameter.  Remove the
parameter to allow us in the future to change the reference to the
global variable with something else, like a function call.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
---
 builtin/notes.c      |  9 ++++-----
 builtin/stripspace.c |  2 +-
 environment.c        | 15 ++++++++++++++-
 environment.h        |  7 +++++++
 fmt-merge-msg.c      |  9 +++------
 rebase-interactive.c |  6 +++---
 sequencer.c          | 10 ++++------
 strbuf.c             | 13 -------------
 strbuf.h             |  9 ---------
 wt-status.c          |  4 ++--
 10 files changed, 38 insertions(+), 46 deletions(-)

diff --git a/builtin/notes.c b/builtin/notes.c
index 9f38863dd5..355ecce07a 100644
--- a/builtin/notes.c
+++ b/builtin/notes.c
@@ -181,7 +181,7 @@ static void write_commented_object(int fd, const struct object_id *object)
 
 	if (strbuf_read(&buf, show.out, 0) < 0)
 		die_errno(_("could not read 'show' output"));
-	strbuf_add_commented_lines(&cbuf, buf.buf, buf.len, comment_line_char);
+	strbuf_add_commented_lines(&cbuf, buf.buf, buf.len);
 	write_or_die(fd, cbuf.buf, cbuf.len);
 
 	strbuf_release(&cbuf);
@@ -209,10 +209,9 @@ static void prepare_note_data(const struct object_id *object, struct note_data *
 			copy_obj_to_fd(fd, old_note);
 
 		strbuf_addch(&buf, '\n');
-		strbuf_add_commented_lines(&buf, "\n", strlen("\n"), comment_line_char);
-		strbuf_add_commented_lines(&buf, _(note_template), strlen(_(note_template)),
-					   comment_line_char);
-		strbuf_add_commented_lines(&buf, "\n", strlen("\n"), comment_line_char);
+		strbuf_add_commented_lines(&buf, "\n", strlen("\n"));
+		strbuf_add_commented_lines(&buf, _(note_template), strlen(_(note_template)));
+		strbuf_add_commented_lines(&buf, "\n", strlen("\n"));
 		write_or_die(fd, buf.buf, buf.len);
 
 		write_commented_object(fd, object);
diff --git a/builtin/stripspace.c b/builtin/stripspace.c
index 7b700a9fb1..11e475760c 100644
--- a/builtin/stripspace.c
+++ b/builtin/stripspace.c
@@ -13,7 +13,7 @@ static void comment_lines(struct strbuf *buf)
 	size_t len;
 
 	msg = strbuf_detach(buf, &len);
-	strbuf_add_commented_lines(buf, msg, len, comment_line_char);
+	strbuf_add_commented_lines(buf, msg, len);
 	free(msg);
 }
 
diff --git a/environment.c b/environment.c
index d9f64cffa0..cc1b85afb6 100644
--- a/environment.c
+++ b/environment.c
@@ -428,9 +428,22 @@ void strbuf_commented_addf(struct strbuf *sb,
 	strbuf_vaddf(&buf, fmt, params);
 	va_end(params);
 
-	strbuf_add_commented_lines(sb, buf.buf, buf.len, comment_line_char);
+	strbuf_add_commented_lines(sb, buf.buf, buf.len);
 	if (incomplete_line)
 		sb->buf[--sb->len] = '\0';
 
 	strbuf_release(&buf);
 }
+
+void strbuf_add_commented_lines(struct strbuf *out,
+				const char *buf, size_t size)
+{
+	static char prefix1[3];
+	static char prefix2[2];
+
+	if (prefix1[0] != comment_line_char) {
+		xsnprintf(prefix1, sizeof(prefix1), "%c ", comment_line_char);
+		xsnprintf(prefix2, sizeof(prefix2), "%c", comment_line_char);
+	}
+	strbuf_add_lines(out, prefix1, prefix2, buf, size);
+}
diff --git a/environment.h b/environment.h
index 5778f5a8e4..f801dbe36e 100644
--- a/environment.h
+++ b/environment.h
@@ -236,4 +236,11 @@ int print_sha1_ellipsis(void);
 __attribute__((format (printf, 2, 3)))
 void strbuf_commented_addf(struct strbuf *sb, const char *fmt, ...);
 
+/**
+ * Add a NUL-terminated string to the buffer. Each line will be prepended
+ * by a comment character and a blank.
+ */
+void strbuf_add_commented_lines(struct strbuf *out,
+				const char *buf, size_t size);
+
 #endif
diff --git a/fmt-merge-msg.c b/fmt-merge-msg.c
index 66e47449a0..adc85d2a72 100644
--- a/fmt-merge-msg.c
+++ b/fmt-merge-msg.c
@@ -509,8 +509,7 @@ static void fmt_tag_signature(struct strbuf *tagbuf,
 	strbuf_complete_line(tagbuf);
 	if (sig->len) {
 		strbuf_addch(tagbuf, '\n');
-		strbuf_add_commented_lines(tagbuf, sig->buf, sig->len,
-					   comment_line_char);
+		strbuf_add_commented_lines(tagbuf, sig->buf, sig->len);
 	}
 }
 
@@ -556,8 +555,7 @@ static void fmt_merge_msg_sigs(struct strbuf *out)
 				strbuf_addch(&tagline, '\n');
 				strbuf_add_commented_lines(&tagline,
 						origins.items[first_tag].string,
-						strlen(origins.items[first_tag].string),
-						comment_line_char);
+						strlen(origins.items[first_tag].string));
 				strbuf_insert(&tagbuf, 0, tagline.buf,
 					      tagline.len);
 				strbuf_release(&tagline);
@@ -565,8 +563,7 @@ static void fmt_merge_msg_sigs(struct strbuf *out)
 			strbuf_addch(&tagbuf, '\n');
 			strbuf_add_commented_lines(&tagbuf,
 					origins.items[i].string,
-					strlen(origins.items[i].string),
-					comment_line_char);
+					strlen(origins.items[i].string));
 			fmt_tag_signature(&tagbuf, &sig, buf, len);
 		}
 		strbuf_release(&payload);
diff --git a/rebase-interactive.c b/rebase-interactive.c
index 3f33da7f03..1138bd37ba 100644
--- a/rebase-interactive.c
+++ b/rebase-interactive.c
@@ -78,7 +78,7 @@ void append_todo_help(int command_count,
 				      shortrevisions, shortonto, command_count);
 	}
 
-	strbuf_add_commented_lines(buf, msg, strlen(msg), comment_line_char);
+	strbuf_add_commented_lines(buf, msg, strlen(msg));
 
 	if (get_missing_commit_check_level() == MISSING_COMMIT_CHECK_ERROR)
 		msg = _("\nDo not remove any line. Use 'drop' "
@@ -87,7 +87,7 @@ void append_todo_help(int command_count,
 		msg = _("\nIf you remove a line here "
 			 "THAT COMMIT WILL BE LOST.\n");
 
-	strbuf_add_commented_lines(buf, msg, strlen(msg), comment_line_char);
+	strbuf_add_commented_lines(buf, msg, strlen(msg));
 
 	if (edit_todo)
 		msg = _("\nYou are editing the todo file "
@@ -98,7 +98,7 @@ void append_todo_help(int command_count,
 		msg = _("\nHowever, if you remove everything, "
 			"the rebase will be aborted.\n\n");
 
-	strbuf_add_commented_lines(buf, msg, strlen(msg), comment_line_char);
+	strbuf_add_commented_lines(buf, msg, strlen(msg));
 }
 
 int edit_todo_list(struct repository *r, struct todo_list *todo_list,
diff --git a/sequencer.c b/sequencer.c
index 5d348a3f12..29c8b5e32b 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -1859,7 +1859,7 @@ static void add_commented_lines(struct strbuf *buf, const void *str, size_t len)
 		s += count;
 		len -= count;
 	}
-	strbuf_add_commented_lines(buf, s, len, comment_line_char);
+	strbuf_add_commented_lines(buf, s, len);
 }
 
 /* Does the current fixup chain contain a squash command? */
@@ -1958,7 +1958,7 @@ static int append_squash_message(struct strbuf *buf, const char *body,
 	strbuf_addf(buf, _(nth_commit_msg_fmt),
 		    ++opts->current_fixup_count + 1);
 	strbuf_addstr(buf, "\n\n");
-	strbuf_add_commented_lines(buf, body, commented_len, comment_line_char);
+	strbuf_add_commented_lines(buf, body, commented_len);
 	/* buf->buf may be reallocated so store an offset into the buffer */
 	fixup_off = buf->len;
 	strbuf_addstr(buf, body + commented_len);
@@ -2048,8 +2048,7 @@ static int update_squash_messages(struct repository *r,
 			      _(first_commit_msg_str));
 		strbuf_addstr(&buf, "\n\n");
 		if (is_fixup_flag(command, flag))
-			strbuf_add_commented_lines(&buf, body, strlen(body),
-						   comment_line_char);
+			strbuf_add_commented_lines(&buf, body, strlen(body));
 		else
 			strbuf_addstr(&buf, body);
 
@@ -2068,8 +2067,7 @@ static int update_squash_messages(struct repository *r,
 		strbuf_addf(&buf, _(skip_nth_commit_msg_fmt),
 			    ++opts->current_fixup_count + 1);
 		strbuf_addstr(&buf, "\n\n");
-		strbuf_add_commented_lines(&buf, body, strlen(body),
-					   comment_line_char);
+		strbuf_add_commented_lines(&buf, body, strlen(body));
 	} else
 		return error(_("unknown command: %d"), command);
 	repo_unuse_commit_buffer(r, commit, message);
diff --git a/strbuf.c b/strbuf.c
index b1717270a2..43027eab76 100644
--- a/strbuf.c
+++ b/strbuf.c
@@ -340,19 +340,6 @@ void strbuf_addf(struct strbuf *sb, const char *fmt, ...)
 	va_end(ap);
 }
 
-void strbuf_add_commented_lines(struct strbuf *out, const char *buf,
-				size_t size, char comment_line_char)
-{
-	static char prefix1[3];
-	static char prefix2[2];
-
-	if (prefix1[0] != comment_line_char) {
-		xsnprintf(prefix1, sizeof(prefix1), "%c ", comment_line_char);
-		xsnprintf(prefix2, sizeof(prefix2), "%c", comment_line_char);
-	}
-	strbuf_add_lines(out, prefix1, prefix2, buf, size);
-}
-
 void strbuf_vaddf(struct strbuf *sb, const char *fmt, va_list ap)
 {
 	int len;
diff --git a/strbuf.h b/strbuf.h
index 4c58dc25e9..ffa2fe3055 100644
--- a/strbuf.h
+++ b/strbuf.h
@@ -282,15 +282,6 @@ void strbuf_remove(struct strbuf *sb, size_t pos, size_t len);
 void strbuf_splice(struct strbuf *sb, size_t pos, size_t len,
 		   const void *data, size_t data_len);
 
-/**
- * Add a NUL-terminated string to the buffer. Each line will be prepended
- * by a comment character and a blank.
- */
-void strbuf_add_commented_lines(struct strbuf *out,
-				const char *buf, size_t size,
-				char comment_line_char);
-
-
 /**
  * Add data of given length to the buffer.
  */
diff --git a/wt-status.c b/wt-status.c
index 54b2775730..b390c77334 100644
--- a/wt-status.c
+++ b/wt-status.c
@@ -1027,7 +1027,7 @@ static void wt_longstatus_print_submodule_summary(struct wt_status *s, int uncom
 	if (s->display_comment_prefix) {
 		size_t len;
 		summary_content = strbuf_detach(&summary, &len);
-		strbuf_add_commented_lines(&summary, summary_content, len, comment_line_char);
+		strbuf_add_commented_lines(&summary, summary_content, len);
 		free(summary_content);
 	}
 
@@ -1103,7 +1103,7 @@ void wt_status_append_cut_line(struct strbuf *buf)
 	const char *explanation = _("Do not modify or remove the line above.\nEverything below it will be ignored.");
 
 	strbuf_commented_addf(buf, "%s", cut_line);
-	strbuf_add_commented_lines(buf, explanation, strlen(explanation), comment_line_char);
+	strbuf_add_commented_lines(buf, explanation, strlen(explanation));
 }
 
 void wt_status_add_cut_line(FILE *fp)
-- 
2.42.0.820.g83a721a137-goog

Re: [RFC PATCH 1/3] strbuf: make add_lines() public

[Junio C Hamano]

Jonathan Tan <jonathantanmy@google.com> writes:

> Subsequent patches will require the ability to add different prefixes
> to different lines (depending on their contents), so make this
> functionality available from outside strbuf.c.

I do not think it is a good idea to force almost everybody to repeat
themselves.  As we can see here, all but just a single caller of
strbuf_add_lines() with this patch pass the same prefix for both
parameters.  If we need to make the current strbuf.c:add_lines()
also available to some specific callers, that is fine, but let's
keep the simpler version that almost everybody uses as-is, and give
the more complex and featureful one that is used only by selected
callers a longer and more cumbersome name.

Thanks.

Re: [RFC PATCH 2/3] strbuf_commented_addf(): drop the comment_line_char parameter

[Junio C Hamano]

Jonathan Tan <jonathantanmy@google.com> writes:

> From: Junio C Hamano <gitster@pobox.com>
>
> All the callers of this function supply the global variable
> comment_line_char as an argument to its second parameter.  Remove
> the parameter to allow us in the future to change the reference to
> the global variable with something else, like a function call.
>
> Signed-off-by: Junio C Hamano <gitster@pobox.com>
> Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
> ---

> diff --git a/environment.c b/environment.c
> index bb3c2a96a3..d9f64cffa0 100644
> --- a/environment.c
> +++ b/environment.c
> @@ -416,3 +416,21 @@ int print_sha1_ellipsis(void)
>  	}
>  	return cached_result;
>  }
> +
> +void strbuf_commented_addf(struct strbuf *sb,
> +			   const char *fmt, ...)
> +{
> +	va_list params;
> +	struct strbuf buf = STRBUF_INIT;
> +	int incomplete_line = sb->len && sb->buf[sb->len - 1] != '\n';
> +
> +	va_start(params, fmt);
> +	strbuf_vaddf(&buf, fmt, params);
> +	va_end(params);
> +
> +	strbuf_add_commented_lines(sb, buf.buf, buf.len, comment_line_char);
> +	if (incomplete_line)
> +		sb->buf[--sb->len] = '\0';
> +
> +	strbuf_release(&buf);
> +}

This moving of the helper function does not belong to the "fix
commented_addf() not to take the comment_line_char" step.

The series should be restructured to have the two patches from me
first, and then your moving some stuff to environment.c, probably.

Re: [RFC PATCH 1/3] strbuf: make add_lines() public

[Junio C Hamano]

Junio C Hamano <gitster@pobox.com> writes:

> Jonathan Tan <jonathantanmy@google.com> writes:
>
>> Subsequent patches will require the ability to add different prefixes
>> to different lines (depending on their contents), so make this
>> functionality available from outside strbuf.c.
>
> I do not think it is a good idea to force almost everybody to repeat
> themselves.  As we can see here, all but just a single caller of
> strbuf_add_lines() with this patch pass the same prefix for both
> parameters.  If we need to make the current strbuf.c:add_lines()
> also available to some specific callers, that is fine, but let's
> keep the simpler version that almost everybody uses as-is, and give
> the more complex and featureful one that is used only by selected
> callers a longer and more cumbersome name.
>
> Thanks.

Another practical downside of this patch is that it breaks other
in-flight topics that adds new users of strbuf_add_lines(), and that
breakage is totally unnecessary.

Re: [RFC PATCH 2/3] strbuf_commented_addf(): drop the comment_line_char parameter

[Jonathan Tan]

Junio C Hamano <gitster@pobox.com> writes:
> This moving of the helper function does not belong to the "fix
> commented_addf() not to take the comment_line_char" step.
> 
> The series should be restructured to have the two patches from me
> first, and then your moving some stuff to environment.c, probably.

This means that #include "environment.h" will be added and then removed
in the same series, but I don't feel too strongly about that. I'll send
an updated set of patches.

[PATCH v2 0/4] Avoid passing global comment_line_char repeatedly

[Jonathan Tan]

Here's an updated patchset. The first 2 are the exact same as what Junio
has sent.

Jonathan Tan (2):
  strbuf: make add_lines() public
  strbuf: move env-using functions to environment.c

Junio C Hamano (2):
  strbuf_commented_addf(): drop the comment_line_char parameter
  strbuf_add_commented_lines(): drop the comment_line_char parameter

 add-patch.c          |  8 +++----
 builtin/branch.c     |  2 +-
 builtin/merge.c      |  8 +++----
 builtin/notes.c      |  9 ++++----
 builtin/stripspace.c |  2 +-
 builtin/tag.c        |  4 ++--
 environment.c        | 32 +++++++++++++++++++++++++++
 environment.h        | 14 ++++++++++++
 fmt-merge-msg.c      |  9 +++-----
 rebase-interactive.c |  8 +++----
 sequencer.c          | 14 ++++++------
 strbuf.c             | 51 +++++++++-----------------------------------
 strbuf.h             | 20 ++++-------------
 wt-status.c          |  6 +++---
 14 files changed, 92 insertions(+), 95 deletions(-)

-- 
2.42.0.820.g83a721a137-goog

[PATCH v2 1/4] strbuf_commented_addf(): drop the comment_line_char parameter

[Jonathan Tan]

From: Junio C Hamano <gitster@pobox.com>

All the callers of this function supply the global variable
comment_line_char as an argument to its second parameter.  Remove
the parameter to allow us in the future to change the reference to
the global variable with something else, like a function call.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 add-patch.c          | 8 ++++----
 builtin/branch.c     | 2 +-
 builtin/merge.c      | 8 ++++----
 builtin/tag.c        | 4 ++--
 rebase-interactive.c | 2 +-
 sequencer.c          | 4 ++--
 strbuf.c             | 3 ++-
 strbuf.h             | 4 ++--
 wt-status.c          | 2 +-
 9 files changed, 19 insertions(+), 18 deletions(-)

diff --git a/add-patch.c b/add-patch.c
index bfe19876cd..471a0037be 100644
--- a/add-patch.c
+++ b/add-patch.c
@@ -1106,11 +1106,11 @@ static int edit_hunk_manually(struct add_p_state *s, struct hunk *hunk)
 	size_t i;
 
 	strbuf_reset(&s->buf);
-	strbuf_commented_addf(&s->buf, comment_line_char,
+	strbuf_commented_addf(&s->buf,
 			      _("Manual hunk edit mode -- see bottom for "
 				"a quick guide.\n"));
 	render_hunk(s, hunk, 0, 0, &s->buf);
-	strbuf_commented_addf(&s->buf, comment_line_char,
+	strbuf_commented_addf(&s->buf,
 			      _("---\n"
 				"To remove '%c' lines, make them ' ' lines "
 				"(context).\n"
@@ -1119,13 +1119,13 @@ static int edit_hunk_manually(struct add_p_state *s, struct hunk *hunk)
 			      s->mode->is_reverse ? '+' : '-',
 			      s->mode->is_reverse ? '-' : '+',
 			      comment_line_char);
-	strbuf_commented_addf(&s->buf, comment_line_char, "%s",
+	strbuf_commented_addf(&s->buf, "%s",
 			      _(s->mode->edit_hunk_hint));
 	/*
 	 * TRANSLATORS: 'it' refers to the patch mentioned in the previous
 	 * messages.
 	 */
-	strbuf_commented_addf(&s->buf, comment_line_char,
+	strbuf_commented_addf(&s->buf,
 			      _("If it does not apply cleanly, you will be "
 				"given an opportunity to\n"
 				"edit again.  If all lines of the hunk are "
diff --git a/builtin/branch.c b/builtin/branch.c
index 2ec190b14a..b2f171e10b 100644
--- a/builtin/branch.c
+++ b/builtin/branch.c
@@ -668,7 +668,7 @@ static int edit_branch_description(const char *branch_name)
 	exists = !read_branch_desc(&buf, branch_name);
 	if (!buf.len || buf.buf[buf.len-1] != '\n')
 		strbuf_addch(&buf, '\n');
-	strbuf_commented_addf(&buf, comment_line_char,
+	strbuf_commented_addf(&buf,
 		    _("Please edit the description for the branch\n"
 		      "  %s\n"
 		      "Lines starting with '%c' will be stripped.\n"),
diff --git a/builtin/merge.c b/builtin/merge.c
index d748d46e13..8f0e8be7c3 100644
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -857,15 +857,15 @@ static void prepare_to_commit(struct commit_list *remoteheads)
 		strbuf_addch(&msg, '\n');
 		if (cleanup_mode == COMMIT_MSG_CLEANUP_SCISSORS) {
 			wt_status_append_cut_line(&msg);
-			strbuf_commented_addf(&msg, comment_line_char, "\n");
+			strbuf_commented_addf(&msg, "\n");
 		}
-		strbuf_commented_addf(&msg, comment_line_char,
+		strbuf_commented_addf(&msg,
 				      _(merge_editor_comment));
 		if (cleanup_mode == COMMIT_MSG_CLEANUP_SCISSORS)
-			strbuf_commented_addf(&msg, comment_line_char,
+			strbuf_commented_addf(&msg,
 					      _(scissors_editor_comment));
 		else
-			strbuf_commented_addf(&msg, comment_line_char,
+			strbuf_commented_addf(&msg,
 				_(no_scissors_editor_comment), comment_line_char);
 	}
 	if (signoff)
diff --git a/builtin/tag.c b/builtin/tag.c
index 3918eacbb5..a85a0d8def 100644
--- a/builtin/tag.c
+++ b/builtin/tag.c
@@ -314,10 +314,10 @@ static void create_tag(const struct object_id *object, const char *object_ref,
 			struct strbuf buf = STRBUF_INIT;
 			strbuf_addch(&buf, '\n');
 			if (opt->cleanup_mode == CLEANUP_ALL)
-				strbuf_commented_addf(&buf, comment_line_char,
+				strbuf_commented_addf(&buf,
 				      _(tag_template), tag, comment_line_char);
 			else
-				strbuf_commented_addf(&buf, comment_line_char,
+				strbuf_commented_addf(&buf,
 				      _(tag_template_nocleanup), tag, comment_line_char);
 			write_or_die(fd, buf.buf, buf.len);
 			strbuf_release(&buf);
diff --git a/rebase-interactive.c b/rebase-interactive.c
index d9718409b3..3f33da7f03 100644
--- a/rebase-interactive.c
+++ b/rebase-interactive.c
@@ -71,7 +71,7 @@ void append_todo_help(int command_count,
 
 	if (!edit_todo) {
 		strbuf_addch(buf, '\n');
-		strbuf_commented_addf(buf, comment_line_char,
+		strbuf_commented_addf(buf,
 				      Q_("Rebase %s onto %s (%d command)",
 					 "Rebase %s onto %s (%d commands)",
 					 command_count),
diff --git a/sequencer.c b/sequencer.c
index d584cac8ed..5d348a3f12 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -675,11 +675,11 @@ void append_conflicts_hint(struct index_state *istate,
 	}
 
 	strbuf_addch(msgbuf, '\n');
-	strbuf_commented_addf(msgbuf, comment_line_char, "Conflicts:\n");
+	strbuf_commented_addf(msgbuf, "Conflicts:\n");
 	for (i = 0; i < istate->cache_nr;) {
 		const struct cache_entry *ce = istate->cache[i++];
 		if (ce_stage(ce)) {
-			strbuf_commented_addf(msgbuf, comment_line_char,
+			strbuf_commented_addf(msgbuf,
 					      "\t%s\n", ce->name);
 			while (i < istate->cache_nr &&
 			       !strcmp(ce->name, istate->cache[i]->name))
diff --git a/strbuf.c b/strbuf.c
index 7827178d8e..15550b2619 100644
--- a/strbuf.c
+++ b/strbuf.c
@@ -1,4 +1,5 @@
 #include "git-compat-util.h"
+#include "environment.h"
 #include "gettext.h"
 #include "hex-ll.h"
 #include "strbuf.h"
@@ -372,7 +373,7 @@ void strbuf_add_commented_lines(struct strbuf *out, const char *buf,
 	add_lines(out, prefix1, prefix2, buf, size);
 }
 
-void strbuf_commented_addf(struct strbuf *sb, char comment_line_char,
+void strbuf_commented_addf(struct strbuf *sb,
 			   const char *fmt, ...)
 {
 	va_list params;
diff --git a/strbuf.h b/strbuf.h
index e959caca87..981617dc77 100644
--- a/strbuf.h
+++ b/strbuf.h
@@ -378,8 +378,8 @@ void strbuf_addf(struct strbuf *sb, const char *fmt, ...);
  * Add a formatted string prepended by a comment character and a
  * blank to the buffer.
  */
-__attribute__((format (printf, 3, 4)))
-void strbuf_commented_addf(struct strbuf *sb, char comment_line_char, const char *fmt, ...);
+__attribute__((format (printf, 2, 3)))
+void strbuf_commented_addf(struct strbuf *sb, const char *fmt, ...);
 
 __attribute__((format (printf,2,0)))
 void strbuf_vaddf(struct strbuf *sb, const char *fmt, va_list ap);
diff --git a/wt-status.c b/wt-status.c
index 9f45bf6949..54b2775730 100644
--- a/wt-status.c
+++ b/wt-status.c
@@ -1102,7 +1102,7 @@ void wt_status_append_cut_line(struct strbuf *buf)
 {
 	const char *explanation = _("Do not modify or remove the line above.\nEverything below it will be ignored.");
 
-	strbuf_commented_addf(buf, comment_line_char, "%s", cut_line);
+	strbuf_commented_addf(buf, "%s", cut_line);
 	strbuf_add_commented_lines(buf, explanation, strlen(explanation), comment_line_char);
 }
 
-- 
2.42.0.820.g83a721a137-goog

[PATCH v2 2/4] strbuf_add_commented_lines(): drop the comment_line_char parameter

[Jonathan Tan]

From: Junio C Hamano <gitster@pobox.com>

All the callers of this function supply the global variable
comment_line_char as an argument to its last parameter.  Remove the
parameter to allow us in the future to change the reference to the
global variable with something else, like a function call.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 builtin/notes.c      |  9 ++++-----
 builtin/stripspace.c |  2 +-
 fmt-merge-msg.c      |  9 +++------
 rebase-interactive.c |  6 +++---
 sequencer.c          | 10 ++++------
 strbuf.c             |  6 +++---
 strbuf.h             |  3 +--
 wt-status.c          |  4 ++--
 8 files changed, 21 insertions(+), 28 deletions(-)

diff --git a/builtin/notes.c b/builtin/notes.c
index 9f38863dd5..355ecce07a 100644
--- a/builtin/notes.c
+++ b/builtin/notes.c
@@ -181,7 +181,7 @@ static void write_commented_object(int fd, const struct object_id *object)
 
 	if (strbuf_read(&buf, show.out, 0) < 0)
 		die_errno(_("could not read 'show' output"));
-	strbuf_add_commented_lines(&cbuf, buf.buf, buf.len, comment_line_char);
+	strbuf_add_commented_lines(&cbuf, buf.buf, buf.len);
 	write_or_die(fd, cbuf.buf, cbuf.len);
 
 	strbuf_release(&cbuf);
@@ -209,10 +209,9 @@ static void prepare_note_data(const struct object_id *object, struct note_data *
 			copy_obj_to_fd(fd, old_note);
 
 		strbuf_addch(&buf, '\n');
-		strbuf_add_commented_lines(&buf, "\n", strlen("\n"), comment_line_char);
-		strbuf_add_commented_lines(&buf, _(note_template), strlen(_(note_template)),
-					   comment_line_char);
-		strbuf_add_commented_lines(&buf, "\n", strlen("\n"), comment_line_char);
+		strbuf_add_commented_lines(&buf, "\n", strlen("\n"));
+		strbuf_add_commented_lines(&buf, _(note_template), strlen(_(note_template)));
+		strbuf_add_commented_lines(&buf, "\n", strlen("\n"));
 		write_or_die(fd, buf.buf, buf.len);
 
 		write_commented_object(fd, object);
diff --git a/builtin/stripspace.c b/builtin/stripspace.c
index 7b700a9fb1..11e475760c 100644
--- a/builtin/stripspace.c
+++ b/builtin/stripspace.c
@@ -13,7 +13,7 @@ static void comment_lines(struct strbuf *buf)
 	size_t len;
 
 	msg = strbuf_detach(buf, &len);
-	strbuf_add_commented_lines(buf, msg, len, comment_line_char);
+	strbuf_add_commented_lines(buf, msg, len);
 	free(msg);
 }
 
diff --git a/fmt-merge-msg.c b/fmt-merge-msg.c
index 66e47449a0..adc85d2a72 100644
--- a/fmt-merge-msg.c
+++ b/fmt-merge-msg.c
@@ -509,8 +509,7 @@ static void fmt_tag_signature(struct strbuf *tagbuf,
 	strbuf_complete_line(tagbuf);
 	if (sig->len) {
 		strbuf_addch(tagbuf, '\n');
-		strbuf_add_commented_lines(tagbuf, sig->buf, sig->len,
-					   comment_line_char);
+		strbuf_add_commented_lines(tagbuf, sig->buf, sig->len);
 	}
 }
 
@@ -556,8 +555,7 @@ static void fmt_merge_msg_sigs(struct strbuf *out)
 				strbuf_addch(&tagline, '\n');
 				strbuf_add_commented_lines(&tagline,
 						origins.items[first_tag].string,
-						strlen(origins.items[first_tag].string),
-						comment_line_char);
+						strlen(origins.items[first_tag].string));
 				strbuf_insert(&tagbuf, 0, tagline.buf,
 					      tagline.len);
 				strbuf_release(&tagline);
@@ -565,8 +563,7 @@ static void fmt_merge_msg_sigs(struct strbuf *out)
 			strbuf_addch(&tagbuf, '\n');
 			strbuf_add_commented_lines(&tagbuf,
 					origins.items[i].string,
-					strlen(origins.items[i].string),
-					comment_line_char);
+					strlen(origins.items[i].string));
 			fmt_tag_signature(&tagbuf, &sig, buf, len);
 		}
 		strbuf_release(&payload);
diff --git a/rebase-interactive.c b/rebase-interactive.c
index 3f33da7f03..1138bd37ba 100644
--- a/rebase-interactive.c
+++ b/rebase-interactive.c
@@ -78,7 +78,7 @@ void append_todo_help(int command_count,
 				      shortrevisions, shortonto, command_count);
 	}
 
-	strbuf_add_commented_lines(buf, msg, strlen(msg), comment_line_char);
+	strbuf_add_commented_lines(buf, msg, strlen(msg));
 
 	if (get_missing_commit_check_level() == MISSING_COMMIT_CHECK_ERROR)
 		msg = _("\nDo not remove any line. Use 'drop' "
@@ -87,7 +87,7 @@ void append_todo_help(int command_count,
 		msg = _("\nIf you remove a line here "
 			 "THAT COMMIT WILL BE LOST.\n");
 
-	strbuf_add_commented_lines(buf, msg, strlen(msg), comment_line_char);
+	strbuf_add_commented_lines(buf, msg, strlen(msg));
 
 	if (edit_todo)
 		msg = _("\nYou are editing the todo file "
@@ -98,7 +98,7 @@ void append_todo_help(int command_count,
 		msg = _("\nHowever, if you remove everything, "
 			"the rebase will be aborted.\n\n");
 
-	strbuf_add_commented_lines(buf, msg, strlen(msg), comment_line_char);
+	strbuf_add_commented_lines(buf, msg, strlen(msg));
 }
 
 int edit_todo_list(struct repository *r, struct todo_list *todo_list,
diff --git a/sequencer.c b/sequencer.c
index 5d348a3f12..29c8b5e32b 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -1859,7 +1859,7 @@ static void add_commented_lines(struct strbuf *buf, const void *str, size_t len)
 		s += count;
 		len -= count;
 	}
-	strbuf_add_commented_lines(buf, s, len, comment_line_char);
+	strbuf_add_commented_lines(buf, s, len);
 }
 
 /* Does the current fixup chain contain a squash command? */
@@ -1958,7 +1958,7 @@ static int append_squash_message(struct strbuf *buf, const char *body,
 	strbuf_addf(buf, _(nth_commit_msg_fmt),
 		    ++opts->current_fixup_count + 1);
 	strbuf_addstr(buf, "\n\n");
-	strbuf_add_commented_lines(buf, body, commented_len, comment_line_char);
+	strbuf_add_commented_lines(buf, body, commented_len);
 	/* buf->buf may be reallocated so store an offset into the buffer */
 	fixup_off = buf->len;
 	strbuf_addstr(buf, body + commented_len);
@@ -2048,8 +2048,7 @@ static int update_squash_messages(struct repository *r,
 			      _(first_commit_msg_str));
 		strbuf_addstr(&buf, "\n\n");
 		if (is_fixup_flag(command, flag))
-			strbuf_add_commented_lines(&buf, body, strlen(body),
-						   comment_line_char);
+			strbuf_add_commented_lines(&buf, body, strlen(body));
 		else
 			strbuf_addstr(&buf, body);
 
@@ -2068,8 +2067,7 @@ static int update_squash_messages(struct repository *r,
 		strbuf_addf(&buf, _(skip_nth_commit_msg_fmt),
 			    ++opts->current_fixup_count + 1);
 		strbuf_addstr(&buf, "\n\n");
-		strbuf_add_commented_lines(&buf, body, strlen(body),
-					   comment_line_char);
+		strbuf_add_commented_lines(&buf, body, strlen(body));
 	} else
 		return error(_("unknown command: %d"), command);
 	repo_unuse_commit_buffer(r, commit, message);
diff --git a/strbuf.c b/strbuf.c
index 15550b2619..2088f7800a 100644
--- a/strbuf.c
+++ b/strbuf.c
@@ -360,8 +360,8 @@ static void add_lines(struct strbuf *out,
 	strbuf_complete_line(out);
 }
 
-void strbuf_add_commented_lines(struct strbuf *out, const char *buf,
-				size_t size, char comment_line_char)
+void strbuf_add_commented_lines(struct strbuf *out,
+				const char *buf, size_t size)
 {
 	static char prefix1[3];
 	static char prefix2[2];
@@ -384,7 +384,7 @@ void strbuf_commented_addf(struct strbuf *sb,
 	strbuf_vaddf(&buf, fmt, params);
 	va_end(params);
 
-	strbuf_add_commented_lines(sb, buf.buf, buf.len, comment_line_char);
+	strbuf_add_commented_lines(sb, buf.buf, buf.len);
 	if (incomplete_line)
 		sb->buf[--sb->len] = '\0';
 
diff --git a/strbuf.h b/strbuf.h
index 981617dc77..4547efa62e 100644
--- a/strbuf.h
+++ b/strbuf.h
@@ -287,8 +287,7 @@ void strbuf_splice(struct strbuf *sb, size_t pos, size_t len,
  * by a comment character and a blank.
  */
 void strbuf_add_commented_lines(struct strbuf *out,
-				const char *buf, size_t size,
-				char comment_line_char);
+				const char *buf, size_t size);
 
 
 /**
diff --git a/wt-status.c b/wt-status.c
index 54b2775730..b390c77334 100644
--- a/wt-status.c
+++ b/wt-status.c
@@ -1027,7 +1027,7 @@ static void wt_longstatus_print_submodule_summary(struct wt_status *s, int uncom
 	if (s->display_comment_prefix) {
 		size_t len;
 		summary_content = strbuf_detach(&summary, &len);
-		strbuf_add_commented_lines(&summary, summary_content, len, comment_line_char);
+		strbuf_add_commented_lines(&summary, summary_content, len);
 		free(summary_content);
 	}
 
@@ -1103,7 +1103,7 @@ void wt_status_append_cut_line(struct strbuf *buf)
 	const char *explanation = _("Do not modify or remove the line above.\nEverything below it will be ignored.");
 
 	strbuf_commented_addf(buf, "%s", cut_line);
-	strbuf_add_commented_lines(buf, explanation, strlen(explanation), comment_line_char);
+	strbuf_add_commented_lines(buf, explanation, strlen(explanation));
 }
 
 void wt_status_add_cut_line(FILE *fp)
-- 
2.42.0.820.g83a721a137-goog

[PATCH v2 3/4] strbuf: make add_lines() public

[Jonathan Tan]

A subsequent patch will require the ability to add different
prefixes to different lines (depending on their contents), so make
this functionality available from outside strbuf.c. The function
name is chosen to avoid a conflict with the existing function named
strbuf_add_lines().

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
---
 strbuf.c | 22 +++++++++++-----------
 strbuf.h |  4 ++++
 2 files changed, 15 insertions(+), 11 deletions(-)

diff --git a/strbuf.c b/strbuf.c
index 2088f7800a..d5ee8874f8 100644
--- a/strbuf.c
+++ b/strbuf.c
@@ -340,24 +340,24 @@ void strbuf_addf(struct strbuf *sb, const char *fmt, ...)
 	va_end(ap);
 }
 
-static void add_lines(struct strbuf *out,
-			const char *prefix1,
-			const char *prefix2,
-			const char *buf, size_t size)
+void strbuf_add_lines_varied_prefix(struct strbuf *sb,
+				    const char *default_prefix,
+				    const char *tab_nl_prefix,
+				    const char *buf, size_t size)
 {
 	while (size) {
 		const char *prefix;
 		const char *next = memchr(buf, '\n', size);
 		next = next ? (next + 1) : (buf + size);
 
-		prefix = ((prefix2 && (buf[0] == '\n' || buf[0] == '\t'))
-			  ? prefix2 : prefix1);
-		strbuf_addstr(out, prefix);
-		strbuf_add(out, buf, next - buf);
+		prefix = (buf[0] == '\n' || buf[0] == '\t')
+			  ? tab_nl_prefix : default_prefix;
+		strbuf_addstr(sb, prefix);
+		strbuf_add(sb, buf, next - buf);
 		size -= next - buf;
 		buf = next;
 	}
-	strbuf_complete_line(out);
+	strbuf_complete_line(sb);
 }
 
 void strbuf_add_commented_lines(struct strbuf *out,
@@ -370,7 +370,7 @@ void strbuf_add_commented_lines(struct strbuf *out,
 		xsnprintf(prefix1, sizeof(prefix1), "%c ", comment_line_char);
 		xsnprintf(prefix2, sizeof(prefix2), "%c", comment_line_char);
 	}
-	add_lines(out, prefix1, prefix2, buf, size);
+	strbuf_add_lines_varied_prefix(out, prefix1, prefix2, buf, size);
 }
 
 void strbuf_commented_addf(struct strbuf *sb,
@@ -751,7 +751,7 @@ ssize_t strbuf_read_file(struct strbuf *sb, const char *path, size_t hint)
 void strbuf_add_lines(struct strbuf *out, const char *prefix,
 		      const char *buf, size_t size)
 {
-	add_lines(out, prefix, NULL, buf, size);
+	strbuf_add_lines_varied_prefix(out, prefix, prefix, buf, size);
 }
 
 void strbuf_addstr_xml_quoted(struct strbuf *buf, const char *s)
diff --git a/strbuf.h b/strbuf.h
index 4547efa62e..a9333ac1ad 100644
--- a/strbuf.h
+++ b/strbuf.h
@@ -601,6 +601,10 @@ void strbuf_add_lines(struct strbuf *sb,
 		      const char *prefix,
 		      const char *buf,
 		      size_t size);
+void strbuf_add_lines_varied_prefix(struct strbuf *sb,
+				    const char *default_prefix,
+				    const char *tab_nl_prefix,
+				    const char *buf, size_t size);
 
 /**
  * Append s to sb, with the characters '<', '>', '&' and '"' converted
-- 
2.42.0.820.g83a721a137-goog

[PATCH v2 4/4] strbuf: move env-using functions to environment.c

[Jonathan Tan]

This eliminates the dependency from strbuf to environment.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
---
 environment.c | 32 ++++++++++++++++++++++++++++++++
 environment.h | 14 ++++++++++++++
 strbuf.c      | 32 --------------------------------
 strbuf.h      | 15 ---------------
 4 files changed, 46 insertions(+), 47 deletions(-)

diff --git a/environment.c b/environment.c
index bb3c2a96a3..942c5b8dd3 100644
--- a/environment.c
+++ b/environment.c
@@ -18,6 +18,7 @@
 #include "refs.h"
 #include "fmt-merge-msg.h"
 #include "commit.h"
+#include "strbuf.h"
 #include "strvec.h"
 #include "object-file.h"
 #include "object-store-ll.h"
@@ -416,3 +417,34 @@ int print_sha1_ellipsis(void)
 	}
 	return cached_result;
 }
+
+void strbuf_commented_addf(struct strbuf *sb,
+			   const char *fmt, ...)
+{
+	va_list params;
+	struct strbuf buf = STRBUF_INIT;
+	int incomplete_line = sb->len && sb->buf[sb->len - 1] != '\n';
+
+	va_start(params, fmt);
+	strbuf_vaddf(&buf, fmt, params);
+	va_end(params);
+
+	strbuf_add_commented_lines(sb, buf.buf, buf.len);
+	if (incomplete_line)
+		sb->buf[--sb->len] = '\0';
+
+	strbuf_release(&buf);
+}
+
+void strbuf_add_commented_lines(struct strbuf *out,
+				const char *buf, size_t size)
+{
+	static char prefix1[3];
+	static char prefix2[2];
+
+	if (prefix1[0] != comment_line_char) {
+		xsnprintf(prefix1, sizeof(prefix1), "%c ", comment_line_char);
+		xsnprintf(prefix2, sizeof(prefix2), "%c", comment_line_char);
+	}
+	strbuf_add_lines_varied_prefix(out, prefix1, prefix2, buf, size);
+}
diff --git a/environment.h b/environment.h
index e5351c9dd9..f801dbe36e 100644
--- a/environment.h
+++ b/environment.h
@@ -229,4 +229,18 @@ extern const char *excludes_file;
  */
 int print_sha1_ellipsis(void);
 
+/**
+ * Add a formatted string prepended by a comment character and a
+ * blank to the buffer.
+ */
+__attribute__((format (printf, 2, 3)))
+void strbuf_commented_addf(struct strbuf *sb, const char *fmt, ...);
+
+/**
+ * Add a NUL-terminated string to the buffer. Each line will be prepended
+ * by a comment character and a blank.
+ */
+void strbuf_add_commented_lines(struct strbuf *out,
+				const char *buf, size_t size);
+
 #endif
diff --git a/strbuf.c b/strbuf.c
index d5ee8874f8..f6c1978ecf 100644
--- a/strbuf.c
+++ b/strbuf.c
@@ -1,5 +1,4 @@
 #include "git-compat-util.h"
-#include "environment.h"
 #include "gettext.h"
 #include "hex-ll.h"
 #include "strbuf.h"
@@ -360,37 +359,6 @@ void strbuf_add_lines_varied_prefix(struct strbuf *sb,
 	strbuf_complete_line(sb);
 }
 
-void strbuf_add_commented_lines(struct strbuf *out,
-				const char *buf, size_t size)
-{
-	static char prefix1[3];
-	static char prefix2[2];
-
-	if (prefix1[0] != comment_line_char) {
-		xsnprintf(prefix1, sizeof(prefix1), "%c ", comment_line_char);
-		xsnprintf(prefix2, sizeof(prefix2), "%c", comment_line_char);
-	}
-	strbuf_add_lines_varied_prefix(out, prefix1, prefix2, buf, size);
-}
-
-void strbuf_commented_addf(struct strbuf *sb,
-			   const char *fmt, ...)
-{
-	va_list params;
-	struct strbuf buf = STRBUF_INIT;
-	int incomplete_line = sb->len && sb->buf[sb->len - 1] != '\n';
-
-	va_start(params, fmt);
-	strbuf_vaddf(&buf, fmt, params);
-	va_end(params);
-
-	strbuf_add_commented_lines(sb, buf.buf, buf.len);
-	if (incomplete_line)
-		sb->buf[--sb->len] = '\0';
-
-	strbuf_release(&buf);
-}
-
 void strbuf_vaddf(struct strbuf *sb, const char *fmt, va_list ap)
 {
 	int len;
diff --git a/strbuf.h b/strbuf.h
index a9333ac1ad..d5f0d4c579 100644
--- a/strbuf.h
+++ b/strbuf.h
@@ -282,14 +282,6 @@ void strbuf_remove(struct strbuf *sb, size_t pos, size_t len);
 void strbuf_splice(struct strbuf *sb, size_t pos, size_t len,
 		   const void *data, size_t data_len);
 
-/**
- * Add a NUL-terminated string to the buffer. Each line will be prepended
- * by a comment character and a blank.
- */
-void strbuf_add_commented_lines(struct strbuf *out,
-				const char *buf, size_t size);
-
-
 /**
  * Add data of given length to the buffer.
  */
@@ -373,13 +365,6 @@ void strbuf_humanise_rate(struct strbuf *buf, off_t bytes);
 __attribute__((format (printf,2,3)))
 void strbuf_addf(struct strbuf *sb, const char *fmt, ...);
 
-/**
- * Add a formatted string prepended by a comment character and a
- * blank to the buffer.
- */
-__attribute__((format (printf, 2, 3)))
-void strbuf_commented_addf(struct strbuf *sb, const char *fmt, ...);
-
 __attribute__((format (printf,2,0)))
 void strbuf_vaddf(struct strbuf *sb, const char *fmt, va_list ap);
 
-- 
2.42.0.820.g83a721a137-goog

Re: [RFC PATCH 2/3] strbuf_commented_addf(): drop the comment_line_char parameter

[Junio C Hamano]

Jonathan Tan <jonathantanmy@google.com> writes:

> Junio C Hamano <gitster@pobox.com> writes:
>> This moving of the helper function does not belong to the "fix
>> commented_addf() not to take the comment_line_char" step.
>> 
>> The series should be restructured to have the two patches from me
>> first, and then your moving some stuff to environment.c, probably.
>
> This means that #include "environment.h" will be added and then removed
> in the same series,

I do prefer it that way, because that is exactly what we are doing.
First we fix the duplicated parameter in the API by relying on the
global, and then we move things around to hide the dependence on the
global.

Thanks.

Re: [PATCH v2 3/4] strbuf: make add_lines() public

[Junio C Hamano]

Jonathan Tan <jonathantanmy@google.com> writes:

> -static void add_lines(struct strbuf *out,
> -			const char *prefix1,
> -			const char *prefix2,
> -			const char *buf, size_t size)
> +void strbuf_add_lines_varied_prefix(struct strbuf *sb,
> +				    const char *default_prefix,
> +				    const char *tab_nl_prefix,
> +				    const char *buf, size_t size)
>  {
>  	while (size) {
>  		const char *prefix;
>  		const char *next = memchr(buf, '\n', size);
>  		next = next ? (next + 1) : (buf + size);
>  
> -		prefix = ((prefix2 && (buf[0] == '\n' || buf[0] == '\t'))
> -			  ? prefix2 : prefix1);
> -		strbuf_addstr(out, prefix);
> -		strbuf_add(out, buf, next - buf);
> +		prefix = (buf[0] == '\n' || buf[0] == '\t')
> +			  ? tab_nl_prefix : default_prefix;
> +		strbuf_addstr(sb, prefix);
> +		strbuf_add(sb, buf, next - buf);

The original allowed callers to pass NULL for the second prefix when
they want to use the same prefix, even for commenting out an empty
line or a line that begins with a tab.  The new one does not allow
the callers to do so.  As long as updating the existing callers are
done carefully, the difference would not matter, but would it help
new callers in the future to rid the usability feature like this
patch does while performing a refactoring?  The loss of feature is
not even documented, by the way.

While "tab_nl" sound a bit more specific than "2", I am not sure if
we made it better.  It does not make it clear why it makes sense to
(and it is necessary to) special case HT and LF.  A developer who is
writing a new caller would not know why there are two prefixes
supported, or why the function is named "varied prefix", with these
names.

Giving a name that explains the reason might help the readability.
I've been thinking what the best name for this function would be but
not successfully.

It may be that we shouldn't take two prefixes in the first place.
The ONLY case callers want to pass prefix2 that is different from
prefix1 is when prefix1 ends with a space, and prefix2 is identical
to prefix1 without the trailing space.  The reason they use such a
pair of prefixes is to avoid leaving a trailing whitespace (when
buf[0] == '\n') or having a space before tab (when buf[0] == '\t')
on the generated lines.

So eventually we may want to have something like this as the final
interface given to the public callers, simply because ...

    strbuf_add_lines_as_comments(struct strbuf *sb,
			         const char *comment_prefix,
				 const char *buf, size_t size)
    {
	while (size) {
            const char *next = memchr(buf, '\n', size);
	    next = next ? (next + 1) : (buf + size);
	    strbuf_addstr(sb, comment_prefix);
	    /* avoid trailing-whitespace and space-before-tab */
	    if (buf[0] != '\n' && buf[0] != '\t')
 		strbuf_addch(sb, ' ');
	    strbuf_add(sb, buf, next - buf);
	    ... loop control ...
	}
        ... strbuf completion ...
    }

... there is no need for totally unrelated two prefix variants.  And
both the function name and the parameter name would be a bit easier
to understand than your version (and far easier than the original).
The function is about commenting out all the lines in buf with the
comment prefix, and most of the time we add a space between the
comment character and the commented out text, but in some cases we
do not want to add the space.

But as I said already, I'd prefer to see a patch that claims to be a
refactoring to do as little as necessary.  Giving it a name better
than add_lines() is inevitable, because you are making it extern.
But I'd prefer to see the parameter naems and the function body left
untouched and kept the same as the original.  It should be left to a
separate step to improve the interface and the implementation.

Thanks.

Re: [PATCH v2 4/4] strbuf: move env-using functions to environment.c

[Junio C Hamano]

Jonathan Tan <jonathantanmy@google.com> writes:

> diff --git a/environment.h b/environment.h
> index e5351c9dd9..f801dbe36e 100644
> --- a/environment.h
> +++ b/environment.h
> @@ -229,4 +229,18 @@ extern const char *excludes_file;
>   */
>  int print_sha1_ellipsis(void);
>  
> +/**
> + * Add a formatted string prepended by a comment character and a
> + * blank to the buffer.
> + */
> +__attribute__((format (printf, 2, 3)))
> +void strbuf_commented_addf(struct strbuf *sb, const char *fmt, ...);
> +
> +/**
> + * Add a NUL-terminated string to the buffer. Each line will be prepended
> + * by a comment character and a blank.
> + */
> +void strbuf_add_commented_lines(struct strbuf *out,
> +				const char *buf, size_t size);
> +

What's your plans for globals kept in ident.c for example?

The reason why I ask is because I do not quite see how making the
use of the global comment-line-char variable hidden like this patch
does would help your libification effort.  There are many settings
that are reasonably expected to be used by many places, and if you
want to avoid them, it appears to me that your only way forward
after applying this patch would be to recreate the implementation
the public git has in environment.[ch] in your version of Git.
You'd have to do something similar for what is in ident.c for the
same reason.

The relative size of the logic necessary to split the original
into lines and prefix the comment prefix character (which is much
larger) and the idea that there is a system wide setting of what the
comment prefix character should be (which is miniscule) makes me
wonder if this is going in the right direction.

Thanks.