format-patch: reduce patch diffstat width to 72

Patches generated by format-patch are meant to be exchanged as emails,
most of the time. And since it's generally agreed that text in mails
should be wrapped around 70 columns or so, make sure these diffstat
follow the convention (especially when used with --cover-letter since we
already defaults to wrapping 72 columns). The default can still be
overriden with command line options.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

2 files changed, 33 insertions, 15 deletions

diff --git a/builtin/log.c b/builtin/log.c
index 96af897403..94ee177d56 100644
--- a/builtin/log.c
+++ b/builtin/log.c
@@ -1617,6 +1617,8 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 		(!rev.diffopt.output_format ||
 		 rev.diffopt.output_format == DIFF_FORMAT_PATCH))
 		rev.diffopt.output_format = DIFF_FORMAT_DIFFSTAT | DIFF_FORMAT_SUMMARY;
+	if (!rev.diffopt.stat_width)
+		rev.diffopt.stat_width = MAIL_DEFAULT_WRAP;
 
 	/* Always generate a patch */
 	rev.diffopt.output_format |= DIFF_FORMAT_PATCH;
diff --git a/t/t4052-stat-output.sh b/t/t4052-stat-output.sh
index 9f563db20a..6e2cf933f7 100755
--- a/t/t4052-stat-output.sh
+++ b/t/t4052-stat-output.sh
@@ -19,17 +19,33 @@ test_expect_success 'preparation' '
 	git commit -m message "$name"
 '
 
+cat >expect72 <<-'EOF'
+ ...aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa | 1 +
+EOF
+test_expect_success "format-patch: small change with long name gives more space to the name" '
+	git format-patch -1 --stdout >output &&
+	grep " | " output >actual &&
+	test_cmp expect72 actual
+'
+
 while read cmd args
 do
-	cat >expect <<-'EOF'
+	cat >expect80 <<-'EOF'
 	 ...aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa | 1 +
 	EOF
 	test_expect_success "$cmd: small change with long name gives more space to the name" '
 		git $cmd $args >output &&
 		grep " | " output >actual &&
-		test_cmp expect actual
+		test_cmp expect80 actual
 	'
+done <<\EOF
+diff HEAD^ HEAD --stat
+show --stat
+log -1 --stat
+EOF
 
+while read cmd args
+do
 	cat >expect <<-'EOF'
 	 ...aaaaaaaaaaaaaaaaaaaaaaaaaaaaa | 1 +
 	EOF
@@ -79,11 +95,11 @@ test_expect_success 'preparation for big change tests' '
 	git commit -m message abcd
 '
 
-cat >expect80 <<'EOF'
- abcd | 1000 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+cat >expect72 <<'EOF'
+ abcd | 1000 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 EOF
-cat >expect80-graph <<'EOF'
-|  abcd | 1000 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+cat >expect72-graph <<'EOF'
+|  abcd | 1000 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 EOF
 cat >expect200 <<'EOF'
  abcd | 1000 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
@@ -107,7 +123,7 @@ do
 		test_cmp "$expect-graph" actual
 	'
 done <<\EOF
-ignores expect80 format-patch -1 --stdout
+ignores expect72 format-patch -1 --stdout
 respects expect200 diff HEAD^ HEAD --stat
 respects expect200 show --stat
 respects expect200 log -1 --stat
@@ -135,7 +151,7 @@ do
 		test_cmp "$expect-graph" actual
 	'
 done <<\EOF
-ignores expect80 format-patch -1 --stdout
+ignores expect72 format-patch -1 --stdout
 respects expect40 diff HEAD^ HEAD --stat
 respects expect40 show --stat
 respects expect40 log -1 --stat
@@ -163,7 +179,7 @@ do
 		test_cmp "$expect-graph" actual
 	'
 done <<\EOF
-ignores expect80 format-patch -1 --stdout
+ignores expect72 format-patch -1 --stdout
 respects expect40 diff HEAD^ HEAD --stat
 respects expect40 show --stat
 respects expect40 log -1 --stat
@@ -250,11 +266,11 @@ show --stat
 log -1 --stat
 EOF
 
-cat >expect80 <<'EOF'
- ...aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa | 1000 ++++++++++++++++++++
+cat >expect72 <<'EOF'
+ ...aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa | 1000 +++++++++++++++++
 EOF
-cat >expect80-graph <<'EOF'
-|  ...aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa | 1000 ++++++++++++++++++++
+cat >expect72-graph <<'EOF'
+|  ...aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa | 1000 +++++++++++++++++
 EOF
 cat >expect200 <<'EOF'
  aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa | 1000 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
@@ -278,7 +294,7 @@ do
 		test_cmp "$expect-graph" actual
 	'
 done <<\EOF
-ignores expect80 format-patch -1 --stdout
+ignores expect72 format-patch -1 --stdout
 respects expect200 diff HEAD^ HEAD --stat
 respects expect200 show --stat
 respects expect200 log -1 --stat
@@ -308,7 +324,7 @@ do
 		test_cmp "$expect-graph" actual
 	'
 done <<\EOF
-ignores expect80 format-patch -1 --stdout
+ignores expect72 format-patch -1 --stdout
 respects expect1 diff HEAD^ HEAD --stat
 respects expect1 show --stat
 respects expect1 log -1 --stat