@matheusbsbs / matheus-bagliano / commits / 89b4183efe

stash: pass --no-color to diff plumbing child processes

After a partial stash, we may clear out the working tree by capturing the output of diff-tree and piping it into git-apply (and likewise we may use diff-index to restore the index). So we most definitely do not want color diff output from that diff-tree process. And it normally would not produce any, since its stdout is not going to a tty, and the default value of color.ui is "auto". However, if GIT_PAGER_IN_USE is set in the environment, that overrides the tty check, and we'll produce a colorized diff that chokes git-apply: $ echo y | GIT_PAGER_IN_USE=1 git stash -p [...] Saved working directory and index state WIP on main: 4f2e2bb foo error: No valid patches in input (allow with "--allow-empty") Cannot remove worktree changes Setting this variable is a relatively silly thing to do, and not something most users would run into. But we sometimes do it in our tests to stimulate color. And it is a user-visible bug, so let's fix it rather than work around it in the tests. The root issue here is that diff-tree (and other diff plumbing) should probably not ever produce color by default. It does so not by parsing color.ui, but because of the baked-in "auto" default from 4c7f1819b3 (make color.ui default to 'auto', 2013-06-10). But changing that is risky; we've had discussions back and forth on the topic over the years. E.g.: https://lore.kernel.org/git/86D0A377-8AFD-460D-A90E-6327C6934DFC@gmail.com/. So let's accept that as the status quo for now and protect ourselves by passing --no-color to the child processes. This is the same thing we did for add-interactive itself in 1c6ffb546b (add--interactive.perl: specify --no-color explicitly, 2020-09-07). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Jeff King committed Sep 8, 2025 at 12:42 UTC 89b4183efe14cc9bda1c8542b8e08dcc66a2b7d5

2 files changed +23 -1

builtin/stash.c

+4 -1

@@ -377,7 +377,7 @@ static int diff_tree_binary(struct strbuf *out, struct object_id *w_commit)

377 * however it should be done together with apply_cached.

378 */

379 cp.git_cmd = 1;

380 - strvec_pushl(&cp.args, "diff-tree", "--binary", NULL);

380 + strvec_pushl(&cp.args, "diff-tree", "--binary", "--no-color", NULL);

381 strvec_pushf(&cp.args, "%s^2^..%s^2", w_commit_hex, w_commit_hex);

382

383 return pipe_command(&cp, NULL, 0, out, 0, NULL, 0);

@@ -1283,6 +1283,7 @@ static int stash_staged(struct stash_info *info, struct strbuf *out_patch,

1283

1284 cp_diff_tree.git_cmd = 1;

1285 strvec_pushl(&cp_diff_tree.args, "diff-tree", "-p", "--binary",

1286 + "--no-color",

1287 "-U1", "HEAD", oid_to_hex(&info->w_tree), "--", NULL);

1288 if (pipe_command(&cp_diff_tree, NULL, 0, out_patch, 0, NULL, 0)) {

1289 ret = -1;

@@ -1345,6 +1346,7 @@ static int stash_patch(struct stash_info *info, const struct pathspec *ps,

1346

1347 cp_diff_tree.git_cmd = 1;

1348 strvec_pushl(&cp_diff_tree.args, "diff-tree", "-p", "-U1", "HEAD",

1349 + "--no-color",

1350 oid_to_hex(&info->w_tree), "--", NULL);

1351 if (pipe_command(&cp_diff_tree, NULL, 0, out_patch, 0, NULL, 0)) {

1352 ret = -1;

@@ -1719,6 +1721,7 @@ static int do_push_stash(const struct pathspec *ps, const char *stash_msg, int q

1721

1722 cp_diff.git_cmd = 1;

1723 strvec_pushl(&cp_diff.args, "diff-index", "-p",

1724 + "--no-color",

1725 "--cached", "--binary", "HEAD", "--",

1726 NULL);

1727 add_pathspecs(&cp_diff.args, ps);

t/t3904-stash-patch.sh

+19

@@ -107,4 +107,23 @@ test_expect_success 'stash -p with split hunk' '

107 ! grep "added line 2" test

108 '

109

110 +test_expect_success 'stash -p not confused by GIT_PAGER_IN_USE' '

111 + echo to-stash >test &&

112 + # Set both GIT_PAGER_IN_USE and TERM. Our goal is to entice any

113 + # diff subprocesses into thinking that they could output

114 + # color, even though their stdout is not going into a tty.

115 + echo y |

116 + GIT_PAGER_IN_USE=1 TERM=vt100 git stash -p &&

117 + git diff --exit-code

118 +'

119 +

120 +test_expect_success 'index push not confused by GIT_PAGER_IN_USE' '

121 + echo index >test &&

122 + git add test &&

123 + echo working-tree >test &&

124 + # As above, we try to entice the child diff into using color.

125 + GIT_PAGER_IN_USE=1 TERM=vt100 git stash push test &&

126 + git diff --exit-code

127 +'

128 +

129 test_done