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, 11 insertions, 7 deletions

diff --git a/pretty.c b/pretty.c
index c8b075d91..b7938e0ef 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_default = 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);
@@ -1720,6 +1722,8 @@ void pp_remainder(struct pretty_print_context *pp,
 		strbuf_grow(sb, linelen + indent + 20);
 		if (indent)
 			pp_handle_indent(pp, sb, indent, line, linelen);
+		else if (pp->expand_tabs_in_log)
+			strbuf_add_tabexpand(sb, line, linelen);
 		else
 			strbuf_add(sb, line, linelen);
 		strbuf_addch(sb, '\n');