pretty: enable --expand-tabs by default for selected pretty formats

"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>

1 files changed, 7 insertions, 0 deletions

diff --git a/revision.c b/revision.c
index e662230..da53b6c 100644
--- a/revision.c
+++ b/revision.c
@@ -1412,8 +1412,10 @@ 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;
+	revs->expand_tabs_in_log_default = 1;
 
 	init_grep_defaults();
 	grep_init(&revs->grep_filter, prefix);
@@ -1917,6 +1919,8 @@ 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;
@@ -2390,6 +2394,9 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, struct s
 	if (revs->first_parent_only && revs->bisect)
 		die(_("--first-parent is incompatible with --bisect"));
 
+	if (revs->expand_tabs_in_log < 0)
+		revs->expand_tabs_in_log = revs->expand_tabs_in_log_default;
+
 	return left;
 }