Subject: [PATCH 04/10] transport: convert pre-push hook to hook.h

From: Adrian Ratiu <[email-masked]>
Date: Thu, 25 Sep 2025 15:53:47 +0300

From: Emily Shaffer <[email-masked]>

Move the pre-push hook away from run-command.h to and over to
the new hook.h library.

In addition to moving the signal and process handling, we use
a custom stdin feeding callback which preserves the original
behaviour of feeding stdin line by line, to avoid buffering
too much data in memory.

Signed-off-by: Emily Shaffer <[email-masked]>
Signed-off-by: Ævar Arnfjörð Bjarmason <[email-masked]>
Signed-off-by: Adrian Ratiu <[email-masked]>
---
 transport.c | 79 ++++++++++++++++++++++-------------------------------
 1 file changed, 32 insertions(+), 47 deletions(-)

diff --git a/transport.c b/transport.c
index 6ac8aa402b..241314806f 100644
--- a/transport.c
+++ b/transport.c
@@ -1316,67 +1316,52 @@ static void die_with_unpushed_submodules(struct string_list *needs_pushing)
 	die(_("Aborting."));
 }
 
-static int run_pre_push_hook(struct transport *transport,
-			     struct ref *remote_refs)
+static int pre_push_hook_feed_stdin(int hook_stdin_fd, void *pp_cb, void *pp_task_cb UNUSED)
 {
-	int ret = 0, x;
-	struct ref *r;
-	struct child_process proc = CHILD_PROCESS_INIT;
-	struct strbuf buf;
-	const char *hook_path = find_hook(the_repository, "pre-push");
-
-	if (!hook_path)
-		return 0;
+	struct hook_cb_data *hook_cb = pp_cb;
+	struct ref *r = hook_cb->options->feed_pipe_ctx;
 
-	strvec_push(&proc.args, hook_path);
-	strvec_push(&proc.args, transport->remote->name);
-	strvec_push(&proc.args, transport->url);
+	if (r) {
+		struct strbuf buf = STRBUF_INIT;
+		int ret = 0;
+		hook_cb->options->feed_pipe_ctx = r->next;
 
-	proc.in = -1;
-	proc.trace2_hook_name = "pre-push";
+		if (!r->peer_ref) return 0;
+		if (r->status == REF_STATUS_REJECT_NONFASTFORWARD) return 0;
+		if (r->status == REF_STATUS_REJECT_STALE) return 0;
+		if (r->status == REF_STATUS_REJECT_REMOTE_UPDATED) return 0;
+		if (r->status == REF_STATUS_UPTODATE) return 0;
 
-	if (start_command(&proc)) {
-		finish_command(&proc);
-		return -1;
-	}
+		strbuf_addf(&buf, "%s %s %s %s\n",
+			    r->peer_ref->name, oid_to_hex(&r->new_oid),
+			    r->name, oid_to_hex(&r->old_oid));
 
-	sigchain_push(SIGPIPE, SIG_IGN);
+		ret = write_in_full(hook_stdin_fd, buf.buf, buf.len);
 
-	strbuf_init(&buf, 256);
+		strbuf_release(&buf);
 
-	for (r = remote_refs; r; r = r->next) {
-		if (!r->peer_ref) continue;
-		if (r->status == REF_STATUS_REJECT_NONFASTFORWARD) continue;
-		if (r->status == REF_STATUS_REJECT_STALE) continue;
-		if (r->status == REF_STATUS_REJECT_REMOTE_UPDATED) continue;
-		if (r->status == REF_STATUS_UPTODATE) continue;
+		/* We do not mind if a hook does not read all refs. */
+		if (ret < 0 && errno != EPIPE)
+			return ret;
 
-		strbuf_reset(&buf);
-		strbuf_addf( &buf, "%s %s %s %s\n",
-			 r->peer_ref->name, oid_to_hex(&r->new_oid),
-			 r->name, oid_to_hex(&r->old_oid));
-
-		if (write_in_full(proc.in, buf.buf, buf.len) < 0) {
-			/* We do not mind if a hook does not read all refs. */
-			if (errno != EPIPE)
-				ret = -1;
-			break;
-		}
+		return 0;
 	}
 
-	strbuf_release(&buf);
+	return 1; /* we ran out of refs: no more input to feed */
+}
 
-	x = close(proc.in);
-	if (!ret)
-		ret = x;
+static int run_pre_push_hook(struct transport *transport,
+			     struct ref *remote_refs)
+{
+	struct run_hooks_opt opt = RUN_HOOKS_OPT_INIT;
 
-	sigchain_pop(SIGPIPE);
+	strvec_push(&opt.args, transport->remote->name);
+	strvec_push(&opt.args, transport->url);
 
-	x = finish_command(&proc);
-	if (!ret)
-		ret = x;
+	opt.feed_pipe = pre_push_hook_feed_stdin;
+	opt.feed_pipe_ctx = remote_refs;
 
-	return ret;
+	return run_hooks_opt(the_repository, "pre-push", &opt);
 }
 
 int transport_push(struct repository *r,
-- 
2.49.1