[PATCH] builtin-branch: improve output when displaying remote branches

[Jay Soffian <jaysoffian@gmail.com>]

When displaying local and remote branches, prefix the remote branch names with
"remotes/" to make the remote branches clear from the local branches. If
displaying only the remote branches, the prefix is not shown since it would be
redundant.

When displaying a remote branch HEAD (which is a sane symref), show what it
points to similar to how "ls -l" show symlinks. Also in this case, do not show
verbose output for the HEAD itself as it is shown immediately below on the
pointed to branch.

Signed-off-by: Jay Soffian <jaysoffian@gmail.com>
---
I think this addresses the feedback I got on the original patch,
http://article.gmane.org/gmane.comp.version-control.git/109161

Some sample output:

$ git branch -a
  master
  next
* wip/branch-show-remote-HEAD-2
  wip/push-docs
  remotes/origin/HEAD -> master
  remotes/origin/html
  remotes/origin/maint
  remotes/origin/man
  remotes/origin/master
  remotes/origin/next
  remotes/origin/pu
  remotes/origin/todo

$ git branch -r
  origin/HEAD -> master
  origin/html
  origin/maint
  origin/man
  origin/master
  origin/next
  origin/pu
  origin/todo

$ git branch -rv
  origin/HEAD -> master
  origin/html           6116912 Autogenerated HTML docs for v1.6.2-rc0-10-gf6b9
  origin/maint          7e1100e gitweb: add $prevent_xss option to prevent XSS by repository content
  origin/man            67cb1a7 Autogenerated manpages for v1.6.2-rc0-10-gf6b9
  origin/master         f6b98e4 git-web--browse: Fix check for /bin/start
  origin/next           417ce12 Merge branch 'master' into next
  origin/pu             9d798e7 Merge branch 'db/foreign-scm' into pu
  origin/todo           5ed7079 What's in update

Notice that the verbose output for HEAD is squelched as it would be identical to
what is shown below in "origin/master". Of course, if <remote>/HEAD does not
resolve as a symref pointing to a branch inside <remote> (I don't know why this
would happen though...), then it is shown like the other branches.

BTW, I noticed that "git branch -a --merged" and "git branch -av --merged"
return a different set of branches. I'm not sure why though (but it isn't due to
this patch).

 builtin-branch.c |   68 ++++++++++++++++++++++++++++++++++++++++-------------
 1 files changed, 51 insertions(+), 17 deletions(-)

diff --git a/builtin-branch.c b/builtin-branch.c
index 56a1971..03ad757 100644
--- a/builtin-branch.c
+++ b/builtin-branch.c
@@ -181,7 +181,8 @@ static int delete_branches(int argc, const char **argv, int force, int kinds)
 
 struct ref_item {
 	char *name;
-	unsigned int kind;
+	char *dest;
+	unsigned int kind, len;
 	struct commit *commit;
 };
 
@@ -193,13 +194,23 @@ struct ref_list {
 	int kinds;
 };
 
+static char *resolve_remote_head_symref(const char *head_name) {
+	unsigned char sha1[20];
+	int flag;
+	const char *refname;
+	refname = resolve_ref(head_name, sha1, 0, &flag);
+	if (refname && (flag & REF_ISSYMREF) &&
+	    !prefixcmp(refname, "refs/remotes/"))
+		return xstrdup(refname + strlen(head_name) - 4);
+	return NULL;
+}
+
 static int append_ref(const char *refname, const unsigned char *sha1, int flags, void *cb_data)
 {
 	struct ref_list *ref_list = (struct ref_list*)(cb_data);
 	struct ref_item *newitem;
 	struct commit *commit;
 	int kind;
-	int len;
 
 	/* Detect kind */
 	if (!prefixcmp(refname, "refs/heads/")) {
@@ -239,9 +250,20 @@ static int append_ref(const char *refname, const unsigned char *sha1, int flags,
 	newitem->name = xstrdup(refname);
 	newitem->kind = kind;
 	newitem->commit = commit;
-	len = strlen(newitem->name);
-	if (len > ref_list->maxwidth)
-		ref_list->maxwidth = len;
+	newitem->len = strlen(newitem->name);
+	newitem->dest = (newitem->kind == REF_REMOTE_BRANCH &&
+			 newitem->len > 5 &&
+			 !strcmp(newitem->name + newitem->len - 5, "/HEAD"))
+			? resolve_remote_head_symref(refname - 13) : NULL;
+	/* adjust for " -> " */
+	if (newitem->dest)
+		newitem->len += strlen(newitem->dest) + 4;
+	/* adjust for "remotes/" */
+	if (newitem->kind == REF_REMOTE_BRANCH &&
+	    ref_list->kinds != REF_REMOTE_BRANCH)
+		newitem->len += 8;
+	if (newitem->len > ref_list->maxwidth)
+		ref_list->maxwidth = newitem->len;
 
 	return 0;
 }
@@ -250,8 +272,11 @@ static void free_ref_list(struct ref_list *ref_list)
 {
 	int i;
 
-	for (i = 0; i < ref_list->index; i++)
+	for (i = 0; i < ref_list->index; i++) {
 		free(ref_list->list[i].name);
+		if (ref_list->list[i].dest)
+			free(ref_list->list[i].dest);
+	}
 	free(ref_list->list);
 }
 
@@ -292,7 +317,7 @@ static int matches_merge_filter(struct commit *commit)
 }
 
 static void print_ref_item(struct ref_item *item, int maxwidth, int verbose,
-			   int abbrev, int current)
+			   int abbrev, int current, char *prefix)
 {
 	char c;
 	int color;
@@ -319,8 +344,13 @@ static void print_ref_item(struct ref_item *item, int maxwidth, int verbose,
 		color = COLOR_BRANCH_CURRENT;
 	}
 
-	if (verbose) {
+	if (item->dest) {
+		printf("%c %s%s%s%s -> %s\n", c, branch_get_color(color),
+		       prefix, item->name,
+		       branch_get_color(COLOR_BRANCH_RESET), item->dest);
+	} else if (verbose) {
 		struct strbuf subject = STRBUF_INIT, stat = STRBUF_INIT;
+		struct strbuf name = STRBUF_INIT;
 		const char *sub = " **** invalid ref ****";
 
 		commit = item->commit;
@@ -333,28 +363,29 @@ static void print_ref_item(struct ref_item *item, int maxwidth, int verbose,
 		if (item->kind == REF_LOCAL_BRANCH)
 			fill_tracking_info(&stat, item->name);
 
+		strbuf_addf(&name, "%s%s", prefix, item->name);
 		printf("%c %s%-*s%s %s %s%s\n", c, branch_get_color(color),
-		       maxwidth, item->name,
+		       maxwidth, name.buf,
 		       branch_get_color(COLOR_BRANCH_RESET),
 		       find_unique_abbrev(item->commit->object.sha1, abbrev),
 		       stat.buf, sub);
 		strbuf_release(&stat);
 		strbuf_release(&subject);
+		strbuf_release(&name);
 	} else {
-		printf("%c %s%s%s\n", c, branch_get_color(color), item->name,
-		       branch_get_color(COLOR_BRANCH_RESET));
+		printf("%c %s%s%s%s\n", c, branch_get_color(color), prefix,
+		       item->name, branch_get_color(COLOR_BRANCH_RESET));
 	}
 }
 
 static int calc_maxwidth(struct ref_list *refs)
 {
-	int i, l, w = 0;
+	int i, w = 0;
 	for (i = 0; i < refs->index; i++) {
 		if (!matches_merge_filter(refs->list[i].commit))
 			continue;
-		l = strlen(refs->list[i].name);
-		if (l > w)
-			w = l;
+		if (refs->list[i].len > w)
+			w = refs->list[i].len;
 	}
 	return w;
 }
@@ -394,7 +425,7 @@ static void print_ref_list(int kinds, int detached, int verbose, int abbrev, str
 		item.commit = head_commit;
 		if (strlen(item.name) > ref_list.maxwidth)
 			ref_list.maxwidth = strlen(item.name);
-		print_ref_item(&item, ref_list.maxwidth, verbose, abbrev, 1);
+		print_ref_item(&item, ref_list.maxwidth, verbose, abbrev, 1, "");
 		free(item.name);
 	}
 
@@ -402,8 +433,11 @@ static void print_ref_list(int kinds, int detached, int verbose, int abbrev, str
 		int current = !detached &&
 			(ref_list.list[i].kind == REF_LOCAL_BRANCH) &&
 			!strcmp(ref_list.list[i].name, head);
+		char *prefix = (kinds != REF_REMOTE_BRANCH &&
+				ref_list.list[i].kind == REF_REMOTE_BRANCH)
+				? "remotes/" : "";
 		print_ref_item(&ref_list.list[i], ref_list.maxwidth, verbose,
-			       abbrev, current);
+			       abbrev, current, prefix);
 	}
 
 	free_ref_list(&ref_list);
-- 
1.6.2.rc0.12.gbd893