receive-pack: don't pass non-existent refs to post-{receive,update} hooks in push deletions

Here is a quick fix-up on top.

Points of interest:

- Get rid of an unnecessary list; just a single bitfield is sufficient; while at it, make skip_update also a bitfield.

- ref_exists(refname) calls resolve_ref() which wants "const char *", and does not touch refname itself. Make it to take "const char *", instead of casting const away in the new caller.

- Properly indent test script. Also:

- Use "cmd <<-EOF" to allow indenting the here text with leading tabs;

- Strip useless use of single quote around "cmd <<'EOF'" inside test_expect_success; they were only stepping out of the sq context while the third argument to test_expect_success was being parsed. A construct like this:

cat >pre-receive.expect <<'EOF'
$orgmaster $newmaster refs/heads/master
EOF

only misleads the readers as if the file is getting literal variable names without substitution, which is not what is going on.

I didn't fix this in this fix-up patch, but you also need to test the case where _ONLY_ deletion of a non-existent ref is requested, in which case, pre-receive and update should be told about it, but post-receive and post-update should not be even run (i.e. test the absense of these post-*.actual files).

 builtin/receive-pack.c |   41 ++++++---------------
 refs.c                 |    2 +-
 refs.h                 |    2 +-
 t/t5516-fetch-push.sh  |   90 ++++++++++++++++++++++++-----------------------
 4 files changed, 60 insertions(+), 75 deletions(-)

builtin/receive-pack.c +12 -29

index 8a0a9d2..b73f18a 100644
@@ -147,32 +147,13 @@ static void write_head_info(void)
 struct command {
 	struct command *next;
 	const char *error_string;
-	unsigned int skip_update;
+	unsigned int skip_update:1,
+		     did_not_exist:1;
 	unsigned char old_sha1[20];
 	unsigned char new_sha1[20];
 	char ref_name[FLEX_ARRAY]; /* more */
 };
 
-/* For invalid refs */
-static struct command **invalid_delete;
-static size_t invalid_delete_nr;
-static size_t invalid_delete_alloc;
-
-static void invalid_delete_append(struct command *cmd)
-{
-	ALLOC_GROW(invalid_delete, invalid_delete_nr + 1, invalid_delete_alloc);
-	invalid_delete[invalid_delete_nr++] = cmd;
-}
-
-static int is_invalid_delete(struct command *cmd)
-{
-	size_t i;
-	for (i = 0; i < invalid_delete_nr; i++)
-		if (invalid_delete[i] == cmd)
-			return 1;
-	return 0;
-}
-
 static const char pre_receive_hook[] = "hooks/pre-receive";
 static const char post_receive_hook[] = "hooks/post-receive";
 

@@ -235,7 +216,7 @@ static int run_receive_hook(struct command *commands, const char *hook_name)
 	int have_input = 0, code;
 
 	for (cmd = commands; !have_input && cmd; cmd = cmd->next) {
-		if (!cmd->error_string && !is_invalid_delete(cmd))
+		if (!cmd->error_string && !cmd->did_not_exist)
 			have_input = 1;
 	}
 

@@ -268,7 +249,7 @@ static int run_receive_hook(struct command *commands, const char *hook_name)
 	}
 
 	for (cmd = commands; cmd; cmd = cmd->next) {
-		if (!cmd->error_string && !is_invalid_delete(cmd)) {
+		if (!cmd->error_string && !cmd->did_not_exist) {
 			size_t n = snprintf(buf, sizeof(buf), "%s %s %s\n",
 				sha1_to_hex(cmd->old_sha1),
 				sha1_to_hex(cmd->new_sha1),

@@ -465,10 +446,13 @@ static const char *update(struct command *cmd)
 
 	if (is_null_sha1(new_sha1)) {
 		if (!parse_object(old_sha1)) {
-			rp_warning("Allowing deletion of corrupt ref.");
 			old_sha1 = NULL;
-			if (!ref_exists((char *) name))
-				invalid_delete_append(cmd);
+			if (ref_exists(name)) {
+				rp_warning("Allowing deletion of corrupt ref.");
+			} else {
+				rp_warning("Deleting a non-existent ref.");
+				cmd->did_not_exist = 1;
+			}
 		}
 		if (delete_ref(namespaced_name, old_sha1, 0)) {
 			rp_error("failed to delete %s", name);

@@ -499,7 +483,7 @@ static void run_update_post_hook(struct command *commands)
 	struct child_process proc;
 
 	for (argc = 0, cmd = commands; cmd; cmd = cmd->next) {
-		if (cmd->error_string || is_invalid_delete(cmd))
+		if (cmd->error_string || cmd->did_not_exist)
 			continue;
 		argc++;
 	}

@@ -510,7 +494,7 @@ static void run_update_post_hook(struct command *commands)
 
 	for (argc = 1, cmd = commands; cmd; cmd = cmd->next) {
 		char *p;
-		if (cmd->error_string || is_invalid_delete(cmd))
+		if (cmd->error_string || cmd->did_not_exist)
 			continue;
 		p = xmalloc(strlen(cmd->ref_name) + 1);
 		strcpy(p, cmd->ref_name);

@@ -888,6 +872,5 @@ int cmd_receive_pack(int argc, const char **argv, const char *prefix)
 	}
 	if (use_sideband)
 		packet_flush(1);
-	free(invalid_delete);
 	return 0;
 }

refs.c +1 -1

index a615043..43e9225 100644
@@ -1851,7 +1851,7 @@ int update_ref(const char *action, const char *refname,
 	return 0;
 }
 
-int ref_exists(char *refname)
+int ref_exists(const char *refname)
 {
 	unsigned char sha1[20];
 	return !!resolve_ref(refname, sha1, 1, NULL);

refs.h +1 -1

index dfb086e..4431205 100644
@@ -57,7 +57,7 @@ extern void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refn
  */
 extern void add_extra_ref(const char *refname, const unsigned char *sha1, int flags);
 extern void clear_extra_refs(void);
-extern int ref_exists(char *);
+extern int ref_exists(const char *);
 
 extern int peel_ref(const char *, unsigned char *);
 

t/t5516-fetch-push.sh +46 -44

index c0d8a0e..47db4b1 100755
@@ -43,33 +43,34 @@ mk_test () {
 mk_test_with_hooks() {
 	mk_test "$@" &&
 	(
-	cd testrepo &&
-	mkdir .git/hooks &&
-	cd .git/hooks &&
+		cd testrepo &&
+		mkdir .git/hooks &&
+		cd .git/hooks &&
 
-	cat >pre-receive <<'EOF' &&
-#!/bin/sh
-cat - >>pre-receive.actual
-EOF
+		cat >pre-receive <<-'EOF' &&
+		#!/bin/sh
+		cat - >>pre-receive.actual
+		EOF
 
-	cat >update <<'EOF' &&
-#!/bin/sh
-printf "%s %s %s\n" "$@" >>update.actual
-EOF
-	cat >post-receive <<'EOF' &&
-#!/bin/sh
-cat - >>post-receive.actual
-EOF
+		cat >update <<-'EOF' &&
+		#!/bin/sh
+		printf "%s %s %s\n" "$@" >>update.actual
+		EOF
 
-	cat >post-update <<'EOF' &&
-#!/bin/sh
-for ref in "$@"
-do
-	printf "%s\n" "$ref" >>post-update.actual
-done
-EOF
+		cat >post-receive <<-'EOF' &&
+		#!/bin/sh
+		cat - >>post-receive.actual
+		EOF
 
-	chmod u+x pre-receive update post-receive post-update
+		cat >post-update <<-'EOF' &&
+		#!/bin/sh
+		for ref in "$@"
+		do
+			printf "%s\n" "$ref" >>post-update.actual
+		done
+		EOF
+
+		chmod +x pre-receive update post-receive post-update
 	)
 }
 

@@ -599,31 +600,32 @@ test_expect_success 'pushing valid refs triggers post-receive and post-update ho
 	orgnext=$(cd testrepo && git show-ref -s --verify refs/heads/next) &&
 	newnext=$_z40 &&
 	git push testrepo refs/heads/master:refs/heads/master :refs/heads/next &&
-	(cd testrepo/.git &&
-	cat >pre-receive.expect <<'EOF' &&
-$orgmaster $newmaster refs/heads/master
-$orgnext $newnext refs/heads/next
-EOF
+	(
+		cd testrepo/.git &&
+		cat >pre-receive.expect <<-EOF &&
+		$orgmaster $newmaster refs/heads/master
+		$orgnext $newnext refs/heads/next
+		EOF
 
-	cat >update.expect <<'EOF' &&
-refs/heads/master $orgmaster $newmaster
-refs/heads/next $orgnext $newnext
-EOF
+		cat >update.expect <<-EOF &&
+		refs/heads/master $orgmaster $newmaster
+		refs/heads/next $orgnext $newnext
+		EOF
 
-	cat >post-receive.expect <<'EOF' &&
-$orgmaster $newmaster refs/heads/master
-$orgnext $newnext refs/heads/next
-EOF
+		cat >post-receive.expect <<-EOF &&
+		$orgmaster $newmaster refs/heads/master
+		$orgnext $newnext refs/heads/next
+		EOF
 
-	cat >post-update.expect <<'EOF' &&
-refs/heads/master
-refs/heads/next
-EOF
+		cat >post-update.expect <<-EOF &&
+		refs/heads/master
+		refs/heads/next
+		EOF
 
-	test_cmp pre-receive.expect pre-receive.actual &&
-	test_cmp update.expect update.actual &&
-	test_cmp post-receive.expect post-receive.actual &&
-	test_cmp post-update.expect post-update.actual
+		test_cmp pre-receive.expect pre-receive.actual &&
+		test_cmp update.expect update.actual &&
+		test_cmp post-receive.expect post-receive.actual &&
+		test_cmp post-update.expect post-update.actual
 	)
 '
 

Signature · 1 line

1.7.7.rc3.4.g8d714

builtin/receive-pack.c struct command { · line 159

Quoted 4 lines · Pang Yan Han

builtin/receive-pack.c +4 -0

+/* For invalid refs */
+static struct command **invalid_delete;
+static size_t invalid_delete_nr;
+static size_t invalid_delete_alloc;

Do you have to have these separately only to keep track of the corner case errors? I would have expected that it would be more natural to mark them by adding a single bitfield to "struct command".

builtin/receive-pack.c static const char *update(struct command *cmd) · line 471

Quoted 7 lines

builtin/receive-pack.c +2 -0

@@ -447,6 +467,8 @@ static const char *update(struct command *cmd)
 		if (!parse_object(old_sha1)) {
 			rp_warning("Allowing deletion of corrupt ref.");
 			old_sha1 = NULL;
+			if (!ref_exists((char *) name))
+				invalid_delete_append(cmd);

This is not an "invalid" delete but deleting a non-existing ref. Perhaps you would want to move the warning and optionally reword it as well, e.g.

	if (!parse_object(old_sha1)) {
        	old_sha1 = NULL;
                if (ref_exists(name)) {
			rp_warning("Allowing deletion of corrupt ref.");
		} else {
			rp_warning("Deleting a ref that does not exist.");
			cmd->did_not_exist = 1;
		}
		...

I am unable to reply this until much later, but are the tests in this patch ok? It's the first time I'm writing test cases for git.

Quoted 2 lines · Pang Yan Han

I am unable to reply this until much later, but are the tests in this patch ok? It's the first time I'm writing test cases for git.

I'll squash in a bit more updates and later publish the result. Thanks.

Sorry for asking, but do I need to reroll this with the fixup in origin/ph/push-to-delete-nothing ? Is the commit message fine especially in light of the changes in the fixup?