[PATCH 10/17] hook: convert 'post-rewrite' hook to config

[Emily Shaffer <emilyshaffer@google.com>]

By using 'hook.h' for 'post-rewrite', we simplify hook invocations by
not needing to put together our own 'struct child_process' and we also
learn to run hooks specified in the config as well as the hook dir.

Signed-off-by: Emily Shaffer <emilyshaffer@google.com>
---
 Documentation/githooks.txt |  2 +
 builtin/am.c               | 18 +++------
 sequencer.c                | 76 +++++++++++++++-----------------------
 3 files changed, 36 insertions(+), 60 deletions(-)

diff --git a/Documentation/githooks.txt b/Documentation/githooks.txt
index 14035ef725..db290984f6 100644
--- a/Documentation/githooks.txt
+++ b/Documentation/githooks.txt
@@ -585,6 +585,8 @@ The hook always runs after the automatic note copying (see
 "notes.rewrite.<command>" in linkgit:git-config[1]) has happened, and
 thus has access to these notes.
 
+Hooks run during 'post-rewrite' will be run in parallel by default.
+
 The following command-specific comments apply:
 
 rebase::
diff --git a/builtin/am.c b/builtin/am.c
index 22d147bc19..c7cad2cb32 100644
--- a/builtin/am.c
+++ b/builtin/am.c
@@ -449,23 +449,15 @@ static int run_applypatch_msg_hook(struct am_state *state)
  */
 static int run_post_rewrite_hook(const struct am_state *state)
 {
-	struct child_process cp = CHILD_PROCESS_INIT;
-	const char *hook = find_hook("post-rewrite");
+	struct run_hooks_opt opt = RUN_HOOKS_OPT_INIT_ASYNC;
 	int ret;
 
-	if (!hook)
-		return 0;
-
-	strvec_push(&cp.args, hook);
-	strvec_push(&cp.args, "rebase");
+	strvec_push(&opt.args, "rebase");
+	opt.path_to_stdin = am_path(state, "rewritten");
 
-	cp.in = xopen(am_path(state, "rewritten"), O_RDONLY);
-	cp.stdout_to_stderr = 1;
-	cp.trace2_hook_name = "post-rewrite";
+	ret = run_hooks("post-rewrite", &opt);
 
-	ret = run_command(&cp);
-
-	close(cp.in);
+	run_hooks_opt_clear(&opt);
 	return ret;
 }
 
diff --git a/sequencer.c b/sequencer.c
index 5a98fd2fbc..4befd862ff 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -35,6 +35,7 @@
 #include "rebase-interactive.h"
 #include "reset.h"
 #include "hook.h"
+#include "string-list.h"
 
 #define GIT_REFLOG_ACTION "GIT_REFLOG_ACTION"
 
@@ -1143,33 +1144,23 @@ int update_head_with_reflog(const struct commit *old_head,
 static int run_rewrite_hook(const struct object_id *oldoid,
 			    const struct object_id *newoid)
 {
-	struct child_process proc = CHILD_PROCESS_INIT;
-	const char *argv[3];
+	struct run_hooks_opt opt = RUN_HOOKS_OPT_INIT_ASYNC;
+	struct strbuf tmp = STRBUF_INIT;
 	int code;
-	struct strbuf sb = STRBUF_INIT;
 
-	argv[0] = find_hook("post-rewrite");
-	if (!argv[0])
-		return 0;
+	strvec_push(&opt.args, "amend");
 
-	argv[1] = "amend";
-	argv[2] = NULL;
-
-	proc.argv = argv;
-	proc.in = -1;
-	proc.stdout_to_stderr = 1;
-	proc.trace2_hook_name = "post-rewrite";
-
-	code = start_command(&proc);
-	if (code)
-		return code;
-	strbuf_addf(&sb, "%s %s\n", oid_to_hex(oldoid), oid_to_hex(newoid));
-	sigchain_push(SIGPIPE, SIG_IGN);
-	write_in_full(proc.in, sb.buf, sb.len);
-	close(proc.in);
-	strbuf_release(&sb);
-	sigchain_pop(SIGPIPE);
-	return finish_command(&proc);
+	strbuf_addf(&tmp,
+		    "%s %s",
+		    oid_to_hex(oldoid),
+		    oid_to_hex(newoid));
+	string_list_append(&opt.str_stdin, tmp.buf);
+
+	code = run_hooks("post-rewrite", &opt);
+
+	run_hooks_opt_clear(&opt);
+	strbuf_release(&tmp);
+	return code;
 }
 
 void commit_post_rewrite(struct repository *r,
@@ -4317,30 +4308,21 @@ static int pick_commits(struct repository *r,
 		flush_rewritten_pending();
 		if (!stat(rebase_path_rewritten_list(), &st) &&
 				st.st_size > 0) {
-			struct child_process child = CHILD_PROCESS_INIT;
-			const char *post_rewrite_hook =
-				find_hook("post-rewrite");
-
-			child.in = open(rebase_path_rewritten_list(), O_RDONLY);
-			child.git_cmd = 1;
-			strvec_push(&child.args, "notes");
-			strvec_push(&child.args, "copy");
-			strvec_push(&child.args, "--for-rewrite=rebase");
+			struct child_process notes_cp = CHILD_PROCESS_INIT;
+			struct run_hooks_opt hook_opt = RUN_HOOKS_OPT_INIT_ASYNC;
+
+			notes_cp.in = open(rebase_path_rewritten_list(), O_RDONLY);
+			notes_cp.git_cmd = 1;
+			strvec_push(&notes_cp.args, "notes");
+			strvec_push(&notes_cp.args, "copy");
+			strvec_push(&notes_cp.args, "--for-rewrite=rebase");
 			/* we don't care if this copying failed */
-			run_command(&child);
-
-			if (post_rewrite_hook) {
-				struct child_process hook = CHILD_PROCESS_INIT;
-
-				hook.in = open(rebase_path_rewritten_list(),
-					O_RDONLY);
-				hook.stdout_to_stderr = 1;
-				hook.trace2_hook_name = "post-rewrite";
-				strvec_push(&hook.args, post_rewrite_hook);
-				strvec_push(&hook.args, "rebase");
-				/* we don't care if this hook failed */
-				run_command(&hook);
-			}
+			run_command(&notes_cp);
+
+			hook_opt.path_to_stdin = rebase_path_rewritten_list();
+			strvec_push(&hook_opt.args, "rebase");
+			run_hooks("post-rewrite", &hook_opt);
+			run_hooks_opt_clear(&hook_opt);
 		}
 		apply_autostash(rebase_path_autostash());
 
-- 
2.28.0.rc0.142.g3c755180ce-goog