[PATCH 1/4] fetch-pack: save shallow file before fetching the pack

["Nguyễn Thái Ngọc Duy" <pclouds@gmail.com>]

index-pack --strict looks up and follows parent commits. If shallow
information is not ready by the time index-pack is run, index-pack may
be lead to non-existent objects. Make fetch-pack save shallow file to
disk before invoking index-pack.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
---
 fetch-pack.c          | 70 ++++++++++++++++++++++++++++-----------------------
 t/t5500-fetch-pack.sh |  7 ++++++
 2 files changed, 45 insertions(+), 32 deletions(-)

diff --git a/fetch-pack.c b/fetch-pack.c
index cef8fde..1f9c5ba 100644
--- a/fetch-pack.c
+++ b/fetch-pack.c
@@ -779,11 +779,44 @@ static int cmp_ref_by_name(const void *a_, const void *b_)
 	return strcmp(a->name, b->name);
 }
 
+static void flush_shallow_to_disk(struct stat *st)
+{
+	static struct lock_file lock;
+	struct cache_time mtime;
+	struct strbuf sb = STRBUF_INIT;
+	char *shallow = git_path("shallow");
+	int fd;
+
+	mtime.sec = st->st_mtime;
+	mtime.nsec = ST_MTIME_NSEC(*st);
+	if (stat(shallow, st)) {
+		if (mtime.sec)
+			die("shallow file was removed during fetch");
+	} else if (st->st_mtime != mtime.sec
+#ifdef USE_NSEC
+		   || ST_MTIME_NSEC(*st) != mtime.nsec
+#endif
+		   )
+		die("shallow file was changed during fetch");
+
+	fd = hold_lock_file_for_update(&lock, shallow,
+				       LOCK_DIE_ON_ERROR);
+	if (!write_shallow_commits(&sb, 0)
+	    || write_in_full(fd, sb.buf, sb.len) != sb.len) {
+		unlink_or_warn(shallow);
+		rollback_lock_file(&lock);
+	} else {
+		commit_lock_file(&lock);
+	}
+	strbuf_release(&sb);
+}
+
 static struct ref *do_fetch_pack(struct fetch_pack_args *args,
 				 int fd[2],
 				 const struct ref *orig_ref,
 				 struct ref **sought, int nr_sought,
-				 char **pack_lockfile)
+				 char **pack_lockfile,
+				 struct stat *shallow_st)
 {
 	struct ref *ref = copy_ref_list(orig_ref);
 	unsigned char sha1[20];
@@ -858,6 +891,8 @@ static struct ref *do_fetch_pack(struct fetch_pack_args *args,
 
 	if (args->stateless_rpc)
 		packet_flush(fd[1]);
+	if (args->depth > 0)
+		flush_shallow_to_disk(shallow_st);
 	if (get_pack(args, fd, pack_lockfile))
 		die("git fetch-pack: fetch failed.");
 
@@ -952,38 +987,9 @@ struct ref *fetch_pack(struct fetch_pack_args *args,
 		packet_flush(fd[1]);
 		die("no matching remote head");
 	}
-	ref_cpy = do_fetch_pack(args, fd, ref, sought, nr_sought, pack_lockfile);
 
-	if (args->depth > 0) {
-		static struct lock_file lock;
-		struct cache_time mtime;
-		struct strbuf sb = STRBUF_INIT;
-		char *shallow = git_path("shallow");
-		int fd;
-
-		mtime.sec = st.st_mtime;
-		mtime.nsec = ST_MTIME_NSEC(st);
-		if (stat(shallow, &st)) {
-			if (mtime.sec)
-				die("shallow file was removed during fetch");
-		} else if (st.st_mtime != mtime.sec
-#ifdef USE_NSEC
-				|| ST_MTIME_NSEC(st) != mtime.nsec
-#endif
-			  )
-			die("shallow file was changed during fetch");
-
-		fd = hold_lock_file_for_update(&lock, shallow,
-					       LOCK_DIE_ON_ERROR);
-		if (!write_shallow_commits(&sb, 0)
-		 || write_in_full(fd, sb.buf, sb.len) != sb.len) {
-			unlink_or_warn(shallow);
-			rollback_lock_file(&lock);
-		} else {
-			commit_lock_file(&lock);
-		}
-		strbuf_release(&sb);
-	}
+	ref_cpy = do_fetch_pack(args, fd, ref, sought, nr_sought,
+				pack_lockfile, &st);
 
 	reprepare_packed_git();
 	return ref_cpy;
diff --git a/t/t5500-fetch-pack.sh b/t/t5500-fetch-pack.sh
index d574085..557b073 100755
--- a/t/t5500-fetch-pack.sh
+++ b/t/t5500-fetch-pack.sh
@@ -135,6 +135,13 @@ test_expect_success 'clone shallow depth 1' '
 	test "`git --git-dir=shallow0/.git rev-list --count HEAD`" = 1
 '
 
+test_expect_success 'clone shallow depth 1 with fsck' '
+	git config --global fetch.fsckobjects true &&
+	git clone --no-single-branch --depth 1 "file://$(pwd)/." shallow0fsck &&
+	test "`git --git-dir=shallow0fsck/.git rev-list --count HEAD`" = 1 &&
+	git config --global --unset fetch.fsckobjects
+'
+
 test_expect_success 'clone shallow' '
 	git clone --no-single-branch --depth 2 "file://$(pwd)/." shallow
 '
-- 
1.8.2.83.gc99314b