[PATCH v4 2/3] pretty: enable --expand-tabs by default for selected pretty formats

[Junio C Hamano <gitster@pobox.com>]

"git log --pretty={medium,full,fuller}" and "git log" by default
prepend 4 spaces to the log message, so it makes sense to enable
the new "expand-tabs" facility by default for these formats.
Add --no-expand-tabs option to override the new default.

The change alone breaks a test in t4201 that runs "git shortlog"
on the output from "git log", and expects that the output from
"git log" does not do such a tab expansion.  Adjust the test to
explicitly disable expand-tabs with --no-expand-tabs.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 Documentation/pretty-options.txt |  6 ++++++
 pretty.c                         | 16 +++++++++-------
 revision.c                       |  3 +++
 t/t4201-shortlog.sh              |  2 +-
 4 files changed, 19 insertions(+), 8 deletions(-)

diff --git a/Documentation/pretty-options.txt b/Documentation/pretty-options.txt
index 4fb5c76..23967b6 100644
--- a/Documentation/pretty-options.txt
+++ b/Documentation/pretty-options.txt
@@ -43,10 +43,16 @@ people using 80-column terminals.
 	commit may be copied to the output.
 
 --expand-tabs::
+--no-expand-tabs::
 	Perform a tab expansion (replace each tab with enough number
 	of spaces to fill to the next display column that is
 	multiple of 8) in the log message before using the message
 	to show in the output.
++
+By default, tabs are expanded in pretty formats that indent the log
+message by 4 spaces (i.e.  'medium', which is the default, 'full',
+and "fuller').  `--no-expand-tabs` option can be used to disable
+this.
 
 ifndef::git-rev-list[]
 --notes[=<ref>]::
diff --git a/pretty.c b/pretty.c
index c8b075d..de22a8c 100644
--- a/pretty.c
+++ b/pretty.c
@@ -16,6 +16,7 @@ static struct cmt_fmt_map {
 	const char *name;
 	enum cmit_fmt format;
 	int is_tformat;
+	int expand_tabs_in_log;
 	int is_alias;
 	const char *user_format;
 } *commit_formats;
@@ -87,13 +88,13 @@ static int git_pretty_formats_config(const char *var, const char *value, void *c
 static void setup_commit_formats(void)
 {
 	struct cmt_fmt_map builtin_formats[] = {
-		{ "raw",	CMIT_FMT_RAW,		0 },
-		{ "medium",	CMIT_FMT_MEDIUM,	0 },
-		{ "short",	CMIT_FMT_SHORT,		0 },
-		{ "email",	CMIT_FMT_EMAIL,		0 },
-		{ "fuller",	CMIT_FMT_FULLER,	0 },
-		{ "full",	CMIT_FMT_FULL,		0 },
-		{ "oneline",	CMIT_FMT_ONELINE,	1 }
+		{ "raw",	CMIT_FMT_RAW,		0,	0 },
+		{ "medium",	CMIT_FMT_MEDIUM,	0,	1 },
+		{ "short",	CMIT_FMT_SHORT,		0,	0 },
+		{ "email",	CMIT_FMT_EMAIL,		0,	0 },
+		{ "fuller",	CMIT_FMT_FULLER,	0,	1 },
+		{ "full",	CMIT_FMT_FULL,		0,	1 },
+		{ "oneline",	CMIT_FMT_ONELINE,	1,	0 }
 	};
 	commit_formats_len = ARRAY_SIZE(builtin_formats);
 	builtin_formats_len = commit_formats_len;
@@ -172,6 +173,7 @@ void get_commit_format(const char *arg, struct rev_info *rev)
 
 	rev->commit_format = commit_format->format;
 	rev->use_terminator = commit_format->is_tformat;
+	rev->expand_tabs_in_log = commit_format->expand_tabs_in_log;
 	if (commit_format->format == CMIT_FMT_USERFORMAT) {
 		save_user_format(rev, commit_format->user_format,
 				 commit_format->is_tformat);
diff --git a/revision.c b/revision.c
index e662230..b1d767a 100644
--- a/revision.c
+++ b/revision.c
@@ -1412,6 +1412,7 @@ void init_revisions(struct rev_info *revs, const char *prefix)
 	revs->skip_count = -1;
 	revs->max_count = -1;
 	revs->max_parents = -1;
+	revs->expand_tabs_in_log = 1;
 
 	revs->commit_format = CMIT_FMT_DEFAULT;
 
@@ -1917,6 +1918,8 @@ static int handle_revision_opt(struct rev_info *revs, int argc, const char **arg
 		get_commit_format(arg+9, revs);
 	} else if (!strcmp(arg, "--expand-tabs")) {
 		revs->expand_tabs_in_log = 1;
+	} else if (!strcmp(arg, "--no-expand-tabs")) {
+		revs->expand_tabs_in_log = 0;
 	} else if (!strcmp(arg, "--show-notes") || !strcmp(arg, "--notes")) {
 		revs->show_notes = 1;
 		revs->show_notes_given = 1;
diff --git a/t/t4201-shortlog.sh b/t/t4201-shortlog.sh
index 7600a3e..2fec948 100755
--- a/t/t4201-shortlog.sh
+++ b/t/t4201-shortlog.sh
@@ -115,7 +115,7 @@ EOF
 '
 
 test_expect_success !MINGW 'shortlog from non-git directory' '
-	git log HEAD >log &&
+	git log --no-expand-tabs HEAD >log &&
 	GIT_DIR=non-existing git shortlog -w <log >out &&
 	test_cmp expect out
 '
-- 
2.8.0-215-gd29a7d9