hook: allow separate std[out|err] streams
The hook API assumes that all hooks merge stdout to stderr. This assumption is proven wrong by pre-push: some of its users actually expect separate stdout and stderr streams and merging them will cause a regression. Therefore this adds a mechanism to allow pre-push to separate the streams, which will be used in the next commit. The mechanism is generic via struct run_hooks_opt just in case there are any more surprise exceptions like this. Reported-by: Chris Darroch <chrisd@apache.org> Suggested-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Adrian Ratiu <adrian.ratiu@collabora.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Adrian Ratiu committed
Jan 28, 2026 at 23:39 UTC
d816637f6c253e3829c4c6e817c7749b3a4f8bf4
2 files changed
+11
-1
hook.c
+1
-1
index 5ddd7678d1..fde1f88ce8 100644
--- a/hook.c
+++ b/hook.c
@@ -81,7 +81,7 @@ static int pick_next_hook(struct child_process *cp,
cp->in = -1;
}
- cp->stdout_to_stderr = 1;
+ cp->stdout_to_stderr = hook_cb->options->stdout_to_stderr;
cp->trace2_hook_name = hook_cb->hook_name;
cp->dir = hook_cb->options->dir;
hook.h
+10
index 2169d4a6bd..2c8a23a569 100644
--- a/hook.h
+++ b/hook.h
@@ -34,6 +34,15 @@ struct run_hooks_opt
*/
int *invoked_hook;
+ /**
+ * Send the hook's stdout to stderr.
+ *
+ * This is the default behavior for all hooks except pre-push,
+ * which has separate stdout and stderr streams for backwards
+ * compatibility reasons.
+ */
+ unsigned int stdout_to_stderr:1;
+
/**
* Path to file which should be piped to stdin for each hook.
*/
@@ -80,6 +89,7 @@ struct run_hooks_opt
#define RUN_HOOKS_OPT_INIT { \
.env = STRVEC_INIT, \
.args = STRVEC_INIT, \
+ .stdout_to_stderr = 1, \
}
struct hook_cb_data {