Subject: [PATCH v7 4/7] receive-pack: new config receive.procReceiveRefs

From: Jiang Xin <[email-masked]>
Date: Fri, 3 Apr 2020 12:08:35 -0400

From: Jiang Xin <[email-masked]>

Add a new multi-valued config variable "receive.procReceiveRefs"
for `receive-pack` command, like the follows:

    git config --system --add receive.procReceiveRefs refs/for/
    git config --system --add receive.procReceiveRefs refs/drafts/

If the specific prefix strings match the reference names of the commands
which are sent by git client to `receive-pack`, these commands will be
executed by an external hook (named "proc-receive"), instead of the
internal `execute_commands` function.

For example, if it is set to "refs/for/", pushing to a reference such as
"refs/for/master" will not create or update reference "refs/for/master",
but may create or update a pull request directly by running the external
hook.

Signed-off-by: Jiang Xin <[email-masked]>
---
 Documentation/config/receive.txt |  14 ++++
 builtin/receive-pack.c           |  43 ++++++++--
 t/t5411-proc-receive-hook.sh     | 130 +++++++++++++++++++++++++++++++
 3 files changed, 180 insertions(+), 7 deletions(-)

diff --git a/Documentation/config/receive.txt b/Documentation/config/receive.txt
index 65f78aac37..0178f2d478 100644
--- a/Documentation/config/receive.txt
+++ b/Documentation/config/receive.txt
@@ -114,6 +114,20 @@ receive.hideRefs::
 	An attempt to update or delete a hidden ref by `git push` is
 	rejected.
 
+receive.procReceiveRefs::
+	This is a multi-valued variable that defines reference prefixes
+	to match the commands in `receive-pack`.  Commands matching the
+	prefixes will be executed by an external hooks "proc-receive",
+	instead of the internal `execute_commands` function.  If this
+	variable is not defined, the "proc-receive" hook will never be
+	used, and all commands will be executed by the internal
+	`execute_commands` function.
+
+	For example, if this variable is set to "refs/for/", pushing to
+	reference such as "refs/for/master" will not create or update a
+	reference named "refs/for/master", but may create or update a
+	pull request directly by running an external hook.
+
 receive.updateServerInfo::
 	If set to true, git-receive-pack will run git-update-server-info
 	after receiving data from git-push and updating refs.
diff --git a/builtin/receive-pack.c b/builtin/receive-pack.c
index eb583093aa..8540829b05 100644
--- a/builtin/receive-pack.c
+++ b/builtin/receive-pack.c
@@ -76,6 +76,7 @@ static struct object_id push_cert_oid;
 static struct signature_check sigcheck;
 static const char *push_cert_nonce;
 static const char *cert_nonce_seed;
+static struct string_list proc_receive_refs;
 
 static const char *NONCE_UNSOLICITED = "UNSOLICITED";
 static const char *NONCE_BAD = "BAD";
@@ -228,6 +229,20 @@ static int receive_pack_config(const char *var, const char *value, void *cb)
 		return 0;
 	}
 
+	if (strcmp(var, "receive.procreceiverefs") == 0) {
+		char *prefix;
+		int len;
+
+		if (!value)
+			return config_error_nonbool(var);
+		prefix = xstrdup(value);
+		len = strlen(prefix);
+		while (len && prefix[len - 1] == '/')
+			prefix[--len] = '\0';
+		string_list_insert(&proc_receive_refs, prefix);
+		return 0;
+	}
+
 	return git_default_config(var, value, cb);
 }
 
@@ -1732,15 +1747,26 @@ static void execute_commands(struct command *commands,
 	/* Try to find commands that have special prefix in their reference names,
 	 * and mark them to run an external "proc-receive" hook later.
 	 */
-	for (cmd = commands; cmd; cmd = cmd->next) {
-		if (!should_process_cmd(cmd))
-			continue;
+	if (proc_receive_refs.nr > 0) {
+		struct strbuf refname_full = STRBUF_INIT;
+		size_t prefix_len;
+
+		strbuf_addstr(&refname_full, get_git_namespace());
+		prefix_len = refname_full.len;
 
-		/* TODO: replace the fixed prefix by looking up git config variables. */
-		if (!strncmp(cmd->ref_name, "refs/for/", 9)) {
-			cmd->run_proc_receive = RUN_PROC_RECEIVE_SCHEDULED;
-			run_proc_receive = 1;
+		for (cmd = commands; cmd; cmd = cmd->next) {
+			if (!should_process_cmd(cmd))
+				continue;
+
+			strbuf_setlen(&refname_full, prefix_len);
+			strbuf_addstr(&refname_full, cmd->ref_name);
+			if (ref_is_matched(&proc_receive_refs, cmd->ref_name, refname_full.buf)) {
+				cmd->run_proc_receive = RUN_PROC_RECEIVE_SCHEDULED;
+				run_proc_receive = 1;
+			}
 		}
+
+		strbuf_release(&refname_full);
 	}
 
 	if (run_receive_hook(commands, "pre-receive", 0, push_options)) {
@@ -2200,6 +2226,8 @@ int cmd_receive_pack(int argc, const char **argv, const char *prefix)
 		OPT_END()
 	};
 
+	string_list_init(&proc_receive_refs, 0);
+
 	packet_trace_identity("receive-pack");
 
 	argc = parse_options(argc, argv, prefix, options, receive_pack_usage, 0);
@@ -2315,5 +2343,6 @@ int cmd_receive_pack(int argc, const char **argv, const char *prefix)
 	oid_array_clear(&shallow);
 	oid_array_clear(&ref);
 	free((void *)push_cert_nonce);
+	string_list_clear(&proc_receive_refs, 0);
 	return 0;
 }
diff --git a/t/t5411-proc-receive-hook.sh b/t/t5411-proc-receive-hook.sh
index a62dadb412..cc5f1adda4 100755
--- a/t/t5411-proc-receive-hook.sh
+++ b/t/t5411-proc-receive-hook.sh
@@ -167,6 +167,14 @@ test_expect_success "cleanup" '
 	)
 '
 
+test_expect_success "add two receive.procReceiveRefs settings" '
+	(
+		cd "$upstream" &&
+		git config --add receive.procReceiveRefs refs/for/ &&
+		git config --add receive.procReceiveRefs refs/review/
+	)
+'
+
 # Refs of upstream : master(A)
 # Refs of workbench: master(A)  tags/v123
 # git push         :                       next(A)  refs/for/master/topic(A)
@@ -721,4 +729,126 @@ test_expect_success "push with options" '
 	test_cmp expect actual
 '
 
+# Refs of upstream : master(A)             next(A)
+# Refs of workbench: master(A)  tags/v123
+test_expect_success "cleanup" '
+	git -C "$upstream" update-ref -d refs/heads/next
+'
+
+test_expect_success "setup proc-receive hook" '
+	cat >"$upstream/hooks/proc-receive" <<-EOF &&
+	#!/bin/sh
+
+	printf >&2 "# proc-receive hook\n"
+
+	test-tool proc-receive -v \
+		-r "$ZERO_OID $A refs/review/a/b/c/topic ok" \
+		-r "$ZERO_OID $A refs/for/next/topic ok" \
+		-r "$ZERO_OID $A refs/for/master/topic ok"
+	EOF
+	chmod a+x "$upstream/hooks/proc-receive"
+'
+
+# Refs of upstream : master(A)
+# Refs of workbench: master(A)  tags/v123
+# git push         :                       refs/for/next/topic(A)  refs/review/a/b/c/topic(A)  refs/for/master/topic(A)
+test_expect_success "report update of all special refs" '
+	git -C workbench push origin \
+		HEAD:refs/for/next/topic \
+		HEAD:refs/review/a/b/c/topic \
+		HEAD:refs/for/master/topic \
+		>out 2>&1 &&
+	make_user_friendly_and_stable_output <out >actual &&
+	cat >expect <<-EOF &&
+	remote: # pre-receive hook
+	remote: pre-receive< <ZERO-OID> <COMMIT-A> refs/for/next/topic
+	remote: pre-receive< <ZERO-OID> <COMMIT-A> refs/review/a/b/c/topic
+	remote: pre-receive< <ZERO-OID> <COMMIT-A> refs/for/master/topic
+	remote: # proc-receive hook
+	remote: proc-receive< <ZERO-OID> <COMMIT-A> refs/for/next/topic
+	remote: proc-receive< <ZERO-OID> <COMMIT-A> refs/review/a/b/c/topic
+	remote: proc-receive< <ZERO-OID> <COMMIT-A> refs/for/master/topic
+	remote: proc-receive> <ZERO-OID> <COMMIT-A> refs/review/a/b/c/topic ok
+	remote: proc-receive> <ZERO-OID> <COMMIT-A> refs/for/next/topic ok
+	remote: proc-receive> <ZERO-OID> <COMMIT-A> refs/for/master/topic ok
+	remote: # post-receive hook
+	remote: post-receive< <ZERO-OID> <COMMIT-A> refs/for/next/topic
+	remote: post-receive< <ZERO-OID> <COMMIT-A> refs/review/a/b/c/topic
+	remote: post-receive< <ZERO-OID> <COMMIT-A> refs/for/master/topic
+	To <URL/of/upstream.git>
+	 * [new reference] HEAD -> refs/for/next/topic
+	 * [new reference] HEAD -> refs/review/a/b/c/topic
+	 * [new reference] HEAD -> refs/for/master/topic
+	EOF
+	test_cmp expect actual &&
+	git -C "$upstream" show-ref >out &&
+	make_user_friendly_and_stable_output <out >actual &&
+	cat >expect <<-EOF &&
+	<COMMIT-A> refs/heads/master
+	EOF
+	test_cmp expect actual
+'
+
+test_expect_success "setup proc-receive hook" '
+	cat >"$upstream/hooks/proc-receive" <<-EOF &&
+	#!/bin/sh
+
+	printf >&2 "# proc-receive hook\n"
+
+	test-tool proc-receive -v \
+		-r "$ZERO_OID $A refs/for/next/topic ok" \
+		-r "$ZERO_OID $A refs/for/master/topic ok"
+	EOF
+	chmod a+x "$upstream/hooks/proc-receive"
+'
+
+# Refs of upstream : master(A)
+# Refs of workbench: master(A)  tags/v123
+# git push         :                       bar(A)  baz(A)  refs/for/next/topic(A)  foo(A)  refs/for/master/topic(A)
+test_expect_success "report mixed refs update" '
+	git -C workbench push origin \
+		HEAD:refs/heads/bar \
+		HEAD:refs/heads/baz \
+		HEAD:refs/for/next/topic \
+		HEAD:refs/heads/foo \
+		HEAD:refs/for/master/topic \
+		>out 2>&1 &&
+	make_user_friendly_and_stable_output <out >actual &&
+	cat >expect <<-EOF &&
+	remote: # pre-receive hook
+	remote: pre-receive< <ZERO-OID> <COMMIT-A> refs/heads/bar
+	remote: pre-receive< <ZERO-OID> <COMMIT-A> refs/heads/baz
+	remote: pre-receive< <ZERO-OID> <COMMIT-A> refs/for/next/topic
+	remote: pre-receive< <ZERO-OID> <COMMIT-A> refs/heads/foo
+	remote: pre-receive< <ZERO-OID> <COMMIT-A> refs/for/master/topic
+	remote: # proc-receive hook
+	remote: proc-receive< <ZERO-OID> <COMMIT-A> refs/for/next/topic
+	remote: proc-receive< <ZERO-OID> <COMMIT-A> refs/for/master/topic
+	remote: proc-receive> <ZERO-OID> <COMMIT-A> refs/for/next/topic ok
+	remote: proc-receive> <ZERO-OID> <COMMIT-A> refs/for/master/topic ok
+	remote: # post-receive hook
+	remote: post-receive< <ZERO-OID> <COMMIT-A> refs/heads/bar
+	remote: post-receive< <ZERO-OID> <COMMIT-A> refs/heads/baz
+	remote: post-receive< <ZERO-OID> <COMMIT-A> refs/for/next/topic
+	remote: post-receive< <ZERO-OID> <COMMIT-A> refs/heads/foo
+	remote: post-receive< <ZERO-OID> <COMMIT-A> refs/for/master/topic
+	To <URL/of/upstream.git>
+	 * [new branch] HEAD -> bar
+	 * [new branch] HEAD -> baz
+	 * [new reference] HEAD -> refs/for/next/topic
+	 * [new branch] HEAD -> foo
+	 * [new reference] HEAD -> refs/for/master/topic
+	EOF
+	test_cmp expect actual &&
+	git -C "$upstream" show-ref >out &&
+	make_user_friendly_and_stable_output <out >actual &&
+	cat >expect <<-EOF &&
+	<COMMIT-A> refs/heads/bar
+	<COMMIT-A> refs/heads/baz
+	<COMMIT-A> refs/heads/foo
+	<COMMIT-A> refs/heads/master
+	EOF
+	test_cmp expect actual
+'
+
 test_done
-- 
2.24.1.15.g448c31058d.agit.4.5