[PATCH 1/4] t4013: add tests for log -p -m --first-parent

[PATCH 1/4] t4013: add tests for log -p -m --first-parent

[Junio C Hamano]

Signed-off-by: Junio C Hamano <gitster@pobox.com>
---

 * This is just to finish off where Pasky has left off.

 t/t4013-diff-various.sh                      |    3 +
 t/t4013/diff.log_-m_-p_--first-parent_master |  100 +++++++++++++
 t/t4013/diff.log_-m_-p_master                |  200 ++++++++++++++++++++++++++
 t/t4013/diff.log_-p_--first-parent_master    |   78 ++++++++++
 4 files changed, 381 insertions(+), 0 deletions(-)
 create mode 100644 t/t4013/diff.log_-m_-p_--first-parent_master
 create mode 100644 t/t4013/diff.log_-m_-p_master
 create mode 100644 t/t4013/diff.log_-p_--first-parent_master

diff --git a/t/t4013-diff-various.sh b/t/t4013-diff-various.sh
index 8e3694e..68cb651 100755
--- a/t/t4013-diff-various.sh
+++ b/t/t4013-diff-various.sh
@@ -204,6 +204,9 @@ log --root --patch-with-stat --summary master
 log --root -c --patch-with-stat --summary master
 # improved by Timo's patch
 log --root --cc --patch-with-stat --summary master
+log -p --first-parent master
+log -m -p --first-parent master
+log -m -p master
 log -SF master
 log -SF -p master
 log --decorate --all
diff --git a/t/t4013/diff.log_-m_-p_--first-parent_master b/t/t4013/diff.log_-m_-p_--first-parent_master
new file mode 100644
index 0000000..7a0073f
--- /dev/null
+++ b/t/t4013/diff.log_-m_-p_--first-parent_master
@@ -0,0 +1,100 @@
+$ git log -m -p --first-parent master
+commit 59d314ad6f356dd08601a4cd5e530381da3e3c64
+Merge: 9a6d494 c7a2ab9
+Author: A U Thor <author@example.com>
+Date:   Mon Jun 26 00:04:00 2006 +0000
+
+    Merge branch 'side'
+
+diff --git a/dir/sub b/dir/sub
+index cead32e..992913c 100644
+--- a/dir/sub
++++ b/dir/sub
+@@ -4,3 +4,5 @@ C
+ D
+ E
+ F
++1
++2
+diff --git a/file0 b/file0
+index b414108..10a8a9f 100644
+--- a/file0
++++ b/file0
+@@ -4,3 +4,6 @@
+ 4
+ 5
+ 6
++A
++B
++C
+
+commit 9a6d4949b6b76956d9d5e26f2791ec2ceff5fdc0
+Author: A U Thor <author@example.com>
+Date:   Mon Jun 26 00:02:00 2006 +0000
+
+    Third
+
+diff --git a/dir/sub b/dir/sub
+index 8422d40..cead32e 100644
+--- a/dir/sub
++++ b/dir/sub
+@@ -2,3 +2,5 @@ A
+ B
+ C
+ D
++E
++F
+diff --git a/file1 b/file1
+new file mode 100644
+index 0000000..b1e6722
+--- /dev/null
++++ b/file1
+@@ -0,0 +1,3 @@
++A
++B
++C
+
+commit 1bde4ae5f36c8d9abe3a0fce0c6aab3c4a12fe44
+Author: A U Thor <author@example.com>
+Date:   Mon Jun 26 00:01:00 2006 +0000
+
+    Second
+    
+    This is the second commit.
+
+diff --git a/dir/sub b/dir/sub
+index 35d242b..8422d40 100644
+--- a/dir/sub
++++ b/dir/sub
+@@ -1,2 +1,4 @@
+ A
+ B
++C
++D
+diff --git a/file0 b/file0
+index 01e79c3..b414108 100644
+--- a/file0
++++ b/file0
+@@ -1,3 +1,6 @@
+ 1
+ 2
+ 3
++4
++5
++6
+diff --git a/file2 b/file2
+deleted file mode 100644
+index 01e79c3..0000000
+--- a/file2
++++ /dev/null
+@@ -1,3 +0,0 @@
+-1
+-2
+-3
+
+commit 444ac553ac7612cc88969031b02b3767fb8a353a
+Author: A U Thor <author@example.com>
+Date:   Mon Jun 26 00:00:00 2006 +0000
+
+    Initial
+$
diff --git a/t/t4013/diff.log_-m_-p_master b/t/t4013/diff.log_-m_-p_master
new file mode 100644
index 0000000..9ca62a0
--- /dev/null
+++ b/t/t4013/diff.log_-m_-p_master
@@ -0,0 +1,200 @@
+$ git log -m -p master
+commit 59d314ad6f356dd08601a4cd5e530381da3e3c64 (from 9a6d4949b6b76956d9d5e26f2791ec2ceff5fdc0)
+Merge: 9a6d494 c7a2ab9
+Author: A U Thor <author@example.com>
+Date:   Mon Jun 26 00:04:00 2006 +0000
+
+    Merge branch 'side'
+
+diff --git a/dir/sub b/dir/sub
+index cead32e..992913c 100644
+--- a/dir/sub
++++ b/dir/sub
+@@ -4,3 +4,5 @@ C
+ D
+ E
+ F
++1
++2
+diff --git a/file0 b/file0
+index b414108..10a8a9f 100644
+--- a/file0
++++ b/file0
+@@ -4,3 +4,6 @@
+ 4
+ 5
+ 6
++A
++B
++C
+
+commit 59d314ad6f356dd08601a4cd5e530381da3e3c64 (from c7a2ab9e8eac7b117442a607d5a9b3950ae34d5a)
+Merge: 9a6d494 c7a2ab9
+Author: A U Thor <author@example.com>
+Date:   Mon Jun 26 00:04:00 2006 +0000
+
+    Merge branch 'side'
+
+diff --git a/dir/sub b/dir/sub
+index 7289e35..992913c 100644
+--- a/dir/sub
++++ b/dir/sub
+@@ -1,4 +1,8 @@
+ A
+ B
++C
++D
++E
++F
+ 1
+ 2
+diff --git a/file0 b/file0
+index f4615da..10a8a9f 100644
+--- a/file0
++++ b/file0
+@@ -1,6 +1,9 @@
+ 1
+ 2
+ 3
++4
++5
++6
+ A
+ B
+ C
+diff --git a/file1 b/file1
+new file mode 100644
+index 0000000..b1e6722
+--- /dev/null
++++ b/file1
+@@ -0,0 +1,3 @@
++A
++B
++C
+diff --git a/file2 b/file2
+deleted file mode 100644
+index 01e79c3..0000000
+--- a/file2
++++ /dev/null
+@@ -1,3 +0,0 @@
+-1
+-2
+-3
+diff --git a/file3 b/file3
+deleted file mode 100644
+index 7289e35..0000000
+--- a/file3
++++ /dev/null
+@@ -1,4 +0,0 @@
+-A
+-B
+-1
+-2
+
+commit c7a2ab9e8eac7b117442a607d5a9b3950ae34d5a
+Author: A U Thor <author@example.com>
+Date:   Mon Jun 26 00:03:00 2006 +0000
+
+    Side
+
+diff --git a/dir/sub b/dir/sub
+index 35d242b..7289e35 100644
+--- a/dir/sub
++++ b/dir/sub
+@@ -1,2 +1,4 @@
+ A
+ B
++1
++2
+diff --git a/file0 b/file0
+index 01e79c3..f4615da 100644
+--- a/file0
++++ b/file0
+@@ -1,3 +1,6 @@
+ 1
+ 2
+ 3
++A
++B
++C
+diff --git a/file3 b/file3
+new file mode 100644
+index 0000000..7289e35
+--- /dev/null
++++ b/file3
+@@ -0,0 +1,4 @@
++A
++B
++1
++2
+
+commit 9a6d4949b6b76956d9d5e26f2791ec2ceff5fdc0
+Author: A U Thor <author@example.com>
+Date:   Mon Jun 26 00:02:00 2006 +0000
+
+    Third
+
+diff --git a/dir/sub b/dir/sub
+index 8422d40..cead32e 100644
+--- a/dir/sub
++++ b/dir/sub
+@@ -2,3 +2,5 @@ A
+ B
+ C
+ D
++E
++F
+diff --git a/file1 b/file1
+new file mode 100644
+index 0000000..b1e6722
+--- /dev/null
++++ b/file1
+@@ -0,0 +1,3 @@
++A
++B
++C
+
+commit 1bde4ae5f36c8d9abe3a0fce0c6aab3c4a12fe44
+Author: A U Thor <author@example.com>
+Date:   Mon Jun 26 00:01:00 2006 +0000
+
+    Second
+    
+    This is the second commit.
+
+diff --git a/dir/sub b/dir/sub
+index 35d242b..8422d40 100644
+--- a/dir/sub
++++ b/dir/sub
+@@ -1,2 +1,4 @@
+ A
+ B
++C
++D
+diff --git a/file0 b/file0
+index 01e79c3..b414108 100644
+--- a/file0
++++ b/file0
+@@ -1,3 +1,6 @@
+ 1
+ 2
+ 3
++4
++5
++6
+diff --git a/file2 b/file2
+deleted file mode 100644
+index 01e79c3..0000000
+--- a/file2
++++ /dev/null
+@@ -1,3 +0,0 @@
+-1
+-2
+-3
+
+commit 444ac553ac7612cc88969031b02b3767fb8a353a
+Author: A U Thor <author@example.com>
+Date:   Mon Jun 26 00:00:00 2006 +0000
+
+    Initial
+$
diff --git a/t/t4013/diff.log_-p_--first-parent_master b/t/t4013/diff.log_-p_--first-parent_master
new file mode 100644
index 0000000..3fc896d
--- /dev/null
+++ b/t/t4013/diff.log_-p_--first-parent_master
@@ -0,0 +1,78 @@
+$ git log -p --first-parent master
+commit 59d314ad6f356dd08601a4cd5e530381da3e3c64
+Merge: 9a6d494 c7a2ab9
+Author: A U Thor <author@example.com>
+Date:   Mon Jun 26 00:04:00 2006 +0000
+
+    Merge branch 'side'
+
+commit 9a6d4949b6b76956d9d5e26f2791ec2ceff5fdc0
+Author: A U Thor <author@example.com>
+Date:   Mon Jun 26 00:02:00 2006 +0000
+
+    Third
+
+diff --git a/dir/sub b/dir/sub
+index 8422d40..cead32e 100644
+--- a/dir/sub
++++ b/dir/sub
+@@ -2,3 +2,5 @@ A
+ B
+ C
+ D
++E
++F
+diff --git a/file1 b/file1
+new file mode 100644
+index 0000000..b1e6722
+--- /dev/null
++++ b/file1
+@@ -0,0 +1,3 @@
++A
++B
++C
+
+commit 1bde4ae5f36c8d9abe3a0fce0c6aab3c4a12fe44
+Author: A U Thor <author@example.com>
+Date:   Mon Jun 26 00:01:00 2006 +0000
+
+    Second
+    
+    This is the second commit.
+
+diff --git a/dir/sub b/dir/sub
+index 35d242b..8422d40 100644
+--- a/dir/sub
++++ b/dir/sub
+@@ -1,2 +1,4 @@
+ A
+ B
++C
++D
+diff --git a/file0 b/file0
+index 01e79c3..b414108 100644
+--- a/file0
++++ b/file0
+@@ -1,3 +1,6 @@
+ 1
+ 2
+ 3
++4
++5
++6
+diff --git a/file2 b/file2
+deleted file mode 100644
+index 01e79c3..0000000
+--- a/file2
++++ /dev/null
+@@ -1,3 +0,0 @@
+-1
+-2
+-3
+
+commit 444ac553ac7612cc88969031b02b3767fb8a353a
+Author: A U Thor <author@example.com>
+Date:   Mon Jun 26 00:00:00 2006 +0000
+
+    Initial
+$
-- 
1.7.0.2.384.g015e

[PATCH 2/4] revision: introduce setup_revision_opt

[Junio C Hamano]

So far the last parameter to setup_revisions() was to specify the default
ref when the command line did not give any (typically "HEAD").  This changes
it to take a pointer to a structure so that we can add other information without
touching too many codepaths in later patches.

There is no functionality change.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
---

 builtin-log.c |   30 ++++++++++++++++++++++--------
 diff-lib.c    |    5 ++++-
 revision.c    |    4 ++--
 revision.h    |    6 +++++-
 wt-status.c   |   15 +++++++++++----
 5 files changed, 44 insertions(+), 16 deletions(-)

diff --git a/builtin-log.c b/builtin-log.c
index 8d16832..dfbf6f2 100644
--- a/builtin-log.c
+++ b/builtin-log.c
@@ -32,7 +32,7 @@ static const char * const builtin_log_usage =
 	"   or: git show [options] <object>...";
 
 static void cmd_log_init(int argc, const char **argv, const char *prefix,
-		      struct rev_info *rev)
+			 struct rev_info *rev, struct setup_revision_opt *opt)
 {
 	int i;
 	int decoration_style = 0;
@@ -56,7 +56,7 @@ static void cmd_log_init(int argc, const char **argv, const char *prefix,
 	 */
 	if (argc == 2 && !strcmp(argv[1], "-h"))
 		usage(builtin_log_usage);
-	argc = setup_revisions(argc, argv, rev, "HEAD");
+	argc = setup_revisions(argc, argv, rev, opt);
 
 	if (!rev->show_notes_given && !rev->pretty_given)
 		rev->show_notes = 1;
@@ -262,6 +262,7 @@ static int git_log_config(const char *var, const char *value, void *cb)
 int cmd_whatchanged(int argc, const char **argv, const char *prefix)
 {
 	struct rev_info rev;
+	struct setup_revision_opt opt;
 
 	git_config(git_log_config, NULL);
 
@@ -271,7 +272,9 @@ int cmd_whatchanged(int argc, const char **argv, const char *prefix)
 	init_revisions(&rev, prefix);
 	rev.diff = 1;
 	rev.simplify_history = 0;
-	cmd_log_init(argc, argv, prefix, &rev);
+	memset(&opt, 0, sizeof(opt));
+	opt.def = "HEAD";
+	cmd_log_init(argc, argv, prefix, &rev, &opt);
 	if (!rev.diffopt.output_format)
 		rev.diffopt.output_format = DIFF_FORMAT_RAW;
 	return cmd_log_walk(&rev);
@@ -328,6 +331,7 @@ int cmd_show(int argc, const char **argv, const char *prefix)
 {
 	struct rev_info rev;
 	struct object_array_entry *objects;
+	struct setup_revision_opt opt;
 	int i, count, ret = 0;
 
 	git_config(git_log_config, NULL);
@@ -342,7 +346,9 @@ int cmd_show(int argc, const char **argv, const char *prefix)
 	rev.always_show_header = 1;
 	rev.ignore_merges = 0;
 	rev.no_walk = 1;
-	cmd_log_init(argc, argv, prefix, &rev);
+	memset(&opt, 0, sizeof(opt));
+	opt.def = "HEAD";
+	cmd_log_init(argc, argv, prefix, &rev, &opt);
 
 	count = rev.pending.nr;
 	objects = rev.pending.objects;
@@ -405,6 +411,7 @@ int cmd_show(int argc, const char **argv, const char *prefix)
 int cmd_log_reflog(int argc, const char **argv, const char *prefix)
 {
 	struct rev_info rev;
+	struct setup_revision_opt opt;
 
 	git_config(git_log_config, NULL);
 
@@ -415,7 +422,9 @@ int cmd_log_reflog(int argc, const char **argv, const char *prefix)
 	init_reflog_walk(&rev.reflog_info);
 	rev.abbrev_commit = 1;
 	rev.verbose_header = 1;
-	cmd_log_init(argc, argv, prefix, &rev);
+	memset(&opt, 0, sizeof(opt));
+	opt.def = "HEAD";
+	cmd_log_init(argc, argv, prefix, &rev, &opt);
 
 	/*
 	 * This means that we override whatever commit format the user gave
@@ -438,6 +447,7 @@ int cmd_log_reflog(int argc, const char **argv, const char *prefix)
 int cmd_log(int argc, const char **argv, const char *prefix)
 {
 	struct rev_info rev;
+	struct setup_revision_opt opt;
 
 	git_config(git_log_config, NULL);
 
@@ -446,7 +456,9 @@ int cmd_log(int argc, const char **argv, const char *prefix)
 
 	init_revisions(&rev, prefix);
 	rev.always_show_header = 1;
-	cmd_log_init(argc, argv, prefix, &rev);
+	memset(&opt, 0, sizeof(opt));
+	opt.def = "HEAD";
+	cmd_log_init(argc, argv, prefix, &rev, &opt);
 	return cmd_log_walk(&rev);
 }
 
@@ -887,6 +899,7 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 	struct commit *commit;
 	struct commit **list = NULL;
 	struct rev_info rev;
+	struct setup_revision_opt s_r_opt;
 	int nr = 0, total, i;
 	int use_stdout = 0;
 	int start_number = -1;
@@ -964,8 +977,9 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 	rev.combine_merges = 0;
 	rev.ignore_merges = 1;
 	DIFF_OPT_SET(&rev.diffopt, RECURSIVE);
-
 	rev.subject_prefix = fmt_patch_subject_prefix;
+	memset(&s_r_opt, 0, sizeof(s_r_opt));
+	s_r_opt.def = "HEAD";
 
 	if (default_attach) {
 		rev.mime_boundary = default_attach;
@@ -1037,7 +1051,7 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 	if (keep_subject && subject_prefix)
 		die ("--subject-prefix and -k are mutually exclusive.");
 
-	argc = setup_revisions(argc, argv, &rev, "HEAD");
+	argc = setup_revisions(argc, argv, &rev, &s_r_opt);
 	if (argc > 1)
 		die ("unrecognized argument: %s", argv[1]);
 
diff --git a/diff-lib.c b/diff-lib.c
index d7e13cb..64976f9 100644
--- a/diff-lib.c
+++ b/diff-lib.c
@@ -510,9 +510,12 @@ int do_diff_cache(const unsigned char *tree_sha1, struct diff_options *opt)
 int index_differs_from(const char *def, int diff_flags)
 {
 	struct rev_info rev;
+	struct setup_revision_opt opt;
 
 	init_revisions(&rev, NULL);
-	setup_revisions(0, NULL, &rev, def);
+	memset(&opt, 0, sizeof(opt));
+	opt.def = def;
+	setup_revisions(0, NULL, &rev, &opt);
 	DIFF_OPT_SET(&rev.diffopt, QUICK);
 	DIFF_OPT_SET(&rev.diffopt, EXIT_WITH_STATUS);
 	rev.diffopt.flags |= diff_flags;
diff --git a/revision.c b/revision.c
index 3ba6d99..25c1bbb 100644
--- a/revision.c
+++ b/revision.c
@@ -1328,7 +1328,7 @@ static void append_prune_data(const char ***prune_data, const char **av)
  * Returns the number of arguments left that weren't recognized
  * (which are also moved to the head of the argument list)
  */
-int setup_revisions(int argc, const char **argv, struct rev_info *revs, const char *def)
+int setup_revisions(int argc, const char **argv, struct rev_info *revs, struct setup_revision_opt *opt)
 {
 	int i, flags, left, seen_dashdash, read_from_stdin;
 	const char **prune_data = NULL;
@@ -1462,7 +1462,7 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, const ch
 		revs->prune_data = get_pathspec(revs->prefix, prune_data);
 
 	if (revs->def == NULL)
-		revs->def = def;
+		revs->def = opt ? opt->def : NULL;
 	if (revs->show_merge)
 		prepare_show_merge(revs);
 	if (revs->def && !revs->pending.nr) {
diff --git a/revision.h b/revision.h
index a14deef..fcc0de8 100644
--- a/revision.h
+++ b/revision.h
@@ -137,8 +137,12 @@ struct rev_info {
 typedef void (*show_early_output_fn_t)(struct rev_info *, struct commit_list *);
 extern volatile show_early_output_fn_t show_early_output;
 
+struct setup_revision_opt {
+	const char *def;
+};
+
 extern void init_revisions(struct rev_info *revs, const char *prefix);
-extern int setup_revisions(int argc, const char **argv, struct rev_info *revs, const char *def);
+extern int setup_revisions(int argc, const char **argv, struct rev_info *revs, struct setup_revision_opt *);
 extern void parse_revision_opt(struct rev_info *revs, struct parse_opt_ctx_t *ctx,
 				 const struct option *options,
 				 const char * const usagestr[]);
diff --git a/wt-status.c b/wt-status.c
index 5807fc3..dcaec7f 100644
--- a/wt-status.c
+++ b/wt-status.c
@@ -290,10 +290,13 @@ static void wt_status_collect_changes_worktree(struct wt_status *s)
 static void wt_status_collect_changes_index(struct wt_status *s)
 {
 	struct rev_info rev;
+	struct setup_revision_opt opt;
 
 	init_revisions(&rev, NULL);
-	setup_revisions(0, NULL, &rev,
-		s->is_initial ? EMPTY_TREE_SHA1_HEX : s->reference);
+	memset(&opt, 0, sizeof(opt));
+	opt.def = s->is_initial ? EMPTY_TREE_SHA1_HEX : s->reference;
+	setup_revisions(0, NULL, &rev, &opt);
+
 	rev.diffopt.output_format |= DIFF_FORMAT_CALLBACK;
 	rev.diffopt.format_callback = wt_status_collect_updated_cb;
 	rev.diffopt.format_callback_data = s;
@@ -512,11 +515,15 @@ static void wt_status_print_untracked(struct wt_status *s)
 static void wt_status_print_verbose(struct wt_status *s)
 {
 	struct rev_info rev;
+	struct setup_revision_opt opt;
 
 	init_revisions(&rev, NULL);
 	DIFF_OPT_SET(&rev.diffopt, ALLOW_TEXTCONV);
-	setup_revisions(0, NULL, &rev,
-		s->is_initial ? EMPTY_TREE_SHA1_HEX : s->reference);
+
+	memset(&opt, 0, sizeof(opt));
+	opt.def = s->is_initial ? EMPTY_TREE_SHA1_HEX : s->reference;
+	setup_revisions(0, NULL, &rev, &opt);
+
 	rev.diffopt.output_format |= DIFF_FORMAT_PATCH;
 	rev.diffopt.detect_rename = 1;
 	rev.diffopt.file = s->fp;
-- 
1.7.0.2.384.g015e

[PATCH 3/4] show -c: show patch text

[Junio C Hamano]

Traditionally, "show" defaulted to "show --cc" (dense combined patch), but
asking for combined patch with "show -c" didn't turn the patch output
format on; the placement of this logic in setup_revisions() dates back to
cd2bdc5 (Common option parsing for "git log --diff" and friends,
2006-04-14).

This unfortunately cannot be done as a trivial change of "if dense
combined is asked, default to patch format" done in setup_revisions() to
"if any combined is asked, default to patch format", as "diff-tree -c"
needs to default to raw, while "diff-tree --cc" needs to default to patch,
and they share the codepath.  These command specific defaults are now
handled in the new "tweak" callback that can be customized by individual
command implementations.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 builtin-diff-tree.c         |   18 ++++++++++++++----
 builtin-log.c               |    7 +++++++
 revision.c                  |    7 +++----
 revision.h                  |    1 +
 t/t4013-diff-various.sh     |    1 +
 t/t4013/diff.show_-c_master |   36 ++++++++++++++++++++++++++++++++++++
 6 files changed, 62 insertions(+), 8 deletions(-)
 create mode 100644 t/t4013/diff.show_-c_master

diff --git a/builtin-diff-tree.c b/builtin-diff-tree.c
index 2380c21..3c78bda 100644
--- a/builtin-diff-tree.c
+++ b/builtin-diff-tree.c
@@ -92,12 +92,23 @@ static const char diff_tree_usage[] =
 "  --root        include the initial commit as diff against /dev/null\n"
 COMMON_DIFF_OPTIONS_HELP;
 
+static void diff_tree_tweak_rev(struct rev_info *rev, struct setup_revision_opt *opt)
+{
+	if (!rev->diffopt.output_format) {
+		if (rev->dense_combined_merges)
+			rev->diffopt.output_format = DIFF_FORMAT_PATCH;
+		else
+			rev->diffopt.output_format = DIFF_FORMAT_RAW;
+	}
+}
+
 int cmd_diff_tree(int argc, const char **argv, const char *prefix)
 {
 	int nr_sha1;
 	char line[1000];
 	struct object *tree1, *tree2;
 	static struct rev_info *opt = &log_tree_opt;
+	struct setup_revision_opt s_r_opt;
 	int read_stdin = 0;
 
 	init_revisions(opt, prefix);
@@ -105,7 +116,9 @@ int cmd_diff_tree(int argc, const char **argv, const char *prefix)
 	opt->abbrev = 0;
 	opt->diff = 1;
 	opt->disable_stdin = 1;
-	argc = setup_revisions(argc, argv, opt, NULL);
+	memset(&s_r_opt, 0, sizeof(s_r_opt));
+	s_r_opt.tweak = diff_tree_tweak_rev;
+	argc = setup_revisions(argc, argv, opt, &s_r_opt);
 
 	while (--argc > 0) {
 		const char *arg = *++argv;
@@ -117,9 +130,6 @@ int cmd_diff_tree(int argc, const char **argv, const char *prefix)
 		usage(diff_tree_usage);
 	}
 
-	if (!opt->diffopt.output_format)
-		opt->diffopt.output_format = DIFF_FORMAT_RAW;
-
 	/*
 	 * NOTE! We expect "a ^b" to be equal to "a..b", so we
 	 * reverse the order of the objects if the second one
diff --git a/builtin-log.c b/builtin-log.c
index dfbf6f2..ab5f60c 100644
--- a/builtin-log.c
+++ b/builtin-log.c
@@ -327,6 +327,12 @@ static int show_tree_object(const unsigned char *sha1,
 	return 0;
 }
 
+static void show_rev_tweak_rev(struct rev_info *rev, struct setup_revision_opt *opt)
+{
+	if (!rev->diffopt.output_format)
+		rev->diffopt.output_format = DIFF_FORMAT_PATCH;
+}
+
 int cmd_show(int argc, const char **argv, const char *prefix)
 {
 	struct rev_info rev;
@@ -348,6 +354,7 @@ int cmd_show(int argc, const char **argv, const char *prefix)
 	rev.no_walk = 1;
 	memset(&opt, 0, sizeof(opt));
 	opt.def = "HEAD";
+	opt.tweak = show_rev_tweak_rev;
 	cmd_log_init(argc, argv, prefix, &rev, &opt);
 
 	count = rev.pending.nr;
diff --git a/revision.c b/revision.c
index 25c1bbb..2ddbb50 100644
--- a/revision.c
+++ b/revision.c
@@ -1463,6 +1463,8 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, struct s
 
 	if (revs->def == NULL)
 		revs->def = opt ? opt->def : NULL;
+	if (opt && opt->tweak)
+		opt->tweak(revs, opt);
 	if (revs->show_merge)
 		prepare_show_merge(revs);
 	if (revs->def && !revs->pending.nr) {
@@ -1496,11 +1498,8 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, struct s
 		if (!revs->full_diff)
 			diff_tree_setup_paths(revs->prune_data, &revs->diffopt);
 	}
-	if (revs->combine_merges) {
+	if (revs->combine_merges)
 		revs->ignore_merges = 0;
-		if (revs->dense_combined_merges && !revs->diffopt.output_format)
-			revs->diffopt.output_format = DIFF_FORMAT_PATCH;
-	}
 	revs->diffopt.abbrev = revs->abbrev;
 	if (diff_setup_done(&revs->diffopt) < 0)
 		die("diff_setup_done failed");
diff --git a/revision.h b/revision.h
index fcc0de8..ceae4ca 100644
--- a/revision.h
+++ b/revision.h
@@ -139,6 +139,7 @@ extern volatile show_early_output_fn_t show_early_output;
 
 struct setup_revision_opt {
 	const char *def;
+	void (*tweak)(struct rev_info *, struct setup_revision_opt *);
 };
 
 extern void init_revisions(struct rev_info *revs, const char *prefix);
diff --git a/t/t4013-diff-various.sh b/t/t4013-diff-various.sh
index 68cb651..8dd93d9 100755
--- a/t/t4013-diff-various.sh
+++ b/t/t4013-diff-various.sh
@@ -238,6 +238,7 @@ show initial
 show --root initial
 show side
 show master
+show -c master
 show --stat side
 show --stat --summary side
 show --patch-with-stat side
diff --git a/t/t4013/diff.show_-c_master b/t/t4013/diff.show_-c_master
new file mode 100644
index 0000000..81aba8d
--- /dev/null
+++ b/t/t4013/diff.show_-c_master
@@ -0,0 +1,36 @@
+$ git show -c master
+commit 59d314ad6f356dd08601a4cd5e530381da3e3c64
+Merge: 9a6d494 c7a2ab9
+Author: A U Thor <author@example.com>
+Date:   Mon Jun 26 00:04:00 2006 +0000
+
+    Merge branch 'side'
+
+diff --combined dir/sub
+index cead32e,7289e35..992913c
+--- a/dir/sub
++++ b/dir/sub
+@@@ -1,6 -1,4 +1,8 @@@
+  A
+  B
+ +C
+ +D
+ +E
+ +F
++ 1
++ 2
+diff --combined file0
+index b414108,f4615da..10a8a9f
+--- a/file0
++++ b/file0
+@@@ -1,6 -1,6 +1,9 @@@
+  1
+  2
+  3
+ +4
+ +5
+ +6
++ A
++ B
++ C
+$
-- 
1.7.0.2.384.g015e

[PATCH 4/4] show --first-parent/-m: do not default to --cc

[Junio C Hamano]

Given that "git show" always shows some diff and does not walk the history
by default, it is natural to expect "git show --first-parent" to show the
difference between the given commit and its first parent.  It also would
be natural, given that "--cc" is the default, "git show -m" to show
pairwise difference from each of the parents.

We however always defaulted to --cc and there was no way to turn it off.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 builtin-log.c                           |   12 +++-
 t/t4013-diff-various.sh                 |    2 +
 t/t4013/diff.show_--first-parent_master |   30 ++++++++++
 t/t4013/diff.show_-m_master             |   93 +++++++++++++++++++++++++++++++
 4 files changed, 134 insertions(+), 3 deletions(-)
 create mode 100644 t/t4013/diff.show_--first-parent_master
 create mode 100644 t/t4013/diff.show_-m_master

diff --git a/builtin-log.c b/builtin-log.c
index ab5f60c..4dd6d2c 100644
--- a/builtin-log.c
+++ b/builtin-log.c
@@ -329,6 +329,15 @@ static int show_tree_object(const unsigned char *sha1,
 
 static void show_rev_tweak_rev(struct rev_info *rev, struct setup_revision_opt *opt)
 {
+	if (rev->ignore_merges) {
+		/* There was no "-m" on the command line */
+		rev->ignore_merges = 0;
+		if (!rev->first_parent_only && !rev->combine_merges) {
+			/* No "--first-parent", "-c", nor "--cc" */
+			rev->combine_merges = 1;
+			rev->dense_combined_merges = 1;
+		}
+	}
 	if (!rev->diffopt.output_format)
 		rev->diffopt.output_format = DIFF_FORMAT_PATCH;
 }
@@ -347,10 +356,7 @@ int cmd_show(int argc, const char **argv, const char *prefix)
 
 	init_revisions(&rev, prefix);
 	rev.diff = 1;
-	rev.combine_merges = 1;
-	rev.dense_combined_merges = 1;
 	rev.always_show_header = 1;
-	rev.ignore_merges = 0;
 	rev.no_walk = 1;
 	memset(&opt, 0, sizeof(opt));
 	opt.def = "HEAD";
diff --git a/t/t4013-diff-various.sh b/t/t4013-diff-various.sh
index 8dd93d9..dae6358 100755
--- a/t/t4013-diff-various.sh
+++ b/t/t4013-diff-various.sh
@@ -239,6 +239,8 @@ show --root initial
 show side
 show master
 show -c master
+show -m master
+show --first-parent master
 show --stat side
 show --stat --summary side
 show --patch-with-stat side
diff --git a/t/t4013/diff.show_--first-parent_master b/t/t4013/diff.show_--first-parent_master
new file mode 100644
index 0000000..3dcbe47
--- /dev/null
+++ b/t/t4013/diff.show_--first-parent_master
@@ -0,0 +1,30 @@
+$ git show --first-parent master
+commit 59d314ad6f356dd08601a4cd5e530381da3e3c64
+Merge: 9a6d494 c7a2ab9
+Author: A U Thor <author@example.com>
+Date:   Mon Jun 26 00:04:00 2006 +0000
+
+    Merge branch 'side'
+
+diff --git a/dir/sub b/dir/sub
+index cead32e..992913c 100644
+--- a/dir/sub
++++ b/dir/sub
+@@ -4,3 +4,5 @@ C
+ D
+ E
+ F
++1
++2
+diff --git a/file0 b/file0
+index b414108..10a8a9f 100644
+--- a/file0
++++ b/file0
+@@ -4,3 +4,6 @@
+ 4
+ 5
+ 6
++A
++B
++C
+$
diff --git a/t/t4013/diff.show_-m_master b/t/t4013/diff.show_-m_master
new file mode 100644
index 0000000..4ea2ee4
--- /dev/null
+++ b/t/t4013/diff.show_-m_master
@@ -0,0 +1,93 @@
+$ git show -m master
+commit 59d314ad6f356dd08601a4cd5e530381da3e3c64 (from 9a6d4949b6b76956d9d5e26f2791ec2ceff5fdc0)
+Merge: 9a6d494 c7a2ab9
+Author: A U Thor <author@example.com>
+Date:   Mon Jun 26 00:04:00 2006 +0000
+
+    Merge branch 'side'
+
+diff --git a/dir/sub b/dir/sub
+index cead32e..992913c 100644
+--- a/dir/sub
++++ b/dir/sub
+@@ -4,3 +4,5 @@ C
+ D
+ E
+ F
++1
++2
+diff --git a/file0 b/file0
+index b414108..10a8a9f 100644
+--- a/file0
++++ b/file0
+@@ -4,3 +4,6 @@
+ 4
+ 5
+ 6
++A
++B
++C
+
+commit 59d314ad6f356dd08601a4cd5e530381da3e3c64 (from c7a2ab9e8eac7b117442a607d5a9b3950ae34d5a)
+Merge: 9a6d494 c7a2ab9
+Author: A U Thor <author@example.com>
+Date:   Mon Jun 26 00:04:00 2006 +0000
+
+    Merge branch 'side'
+
+diff --git a/dir/sub b/dir/sub
+index 7289e35..992913c 100644
+--- a/dir/sub
++++ b/dir/sub
+@@ -1,4 +1,8 @@
+ A
+ B
++C
++D
++E
++F
+ 1
+ 2
+diff --git a/file0 b/file0
+index f4615da..10a8a9f 100644
+--- a/file0
++++ b/file0
+@@ -1,6 +1,9 @@
+ 1
+ 2
+ 3
++4
++5
++6
+ A
+ B
+ C
+diff --git a/file1 b/file1
+new file mode 100644
+index 0000000..b1e6722
+--- /dev/null
++++ b/file1
+@@ -0,0 +1,3 @@
++A
++B
++C
+diff --git a/file2 b/file2
+deleted file mode 100644
+index 01e79c3..0000000
+--- a/file2
++++ /dev/null
+@@ -1,3 +0,0 @@
+-1
+-2
+-3
+diff --git a/file3 b/file3
+deleted file mode 100644
+index 7289e35..0000000
+--- a/file3
++++ /dev/null
+@@ -1,4 +0,0 @@
+-A
+-B
+-1
+-2
+$
-- 
1.7.0.2.384.g015e