path: root/shallow.c
diff options
authorJonathan Tan <>2019-01-10 19:36:45 (GMT)
committerJunio C Hamano <>2019-01-10 22:53:35 (GMT)
commitbd0b42aed3084bf66557485fd7d87e975a4f6d4e (patch)
tree3687936d9bd551986a68a23e665ec169e08194bd /shallow.c
parentecbdaf0899161c067986e9d9d564586d4b045d62 (diff)
fetch-pack: do not take shallow lock unnecessarily
When fetching using protocol v2, the remote may send a "shallow-info" section if the client is shallow. If so, Git as the client currently takes the shallow file lock, even if the "shallow-info" section is empty. This is not a problem except that Git does not support taking the shallow file lock after modifying the shallow file, because is_repository_shallow() stores information that is never cleared. And this take-after-modify occurs when Git does a tag-following fetch from a shallow repository on a transport that does not support tag following (since in this case, 2 fetches are performed). To solve this issue, take the shallow file lock (and perform all other shallow processing) only if the "shallow-info" section is non-empty; otherwise, behave as if it were empty. A full solution (probably, ensuring that any action of committing shallow file locks also includes clearing the information stored by is_repository_shallow()) would solve the issue without need for this patch, but this patch is independently useful (as an optimization to prevent writing a file in an unnecessary case), hence why I wrote it. I have included a NEEDSWORK outlining the full solution. Signed-off-by: Jonathan Tan <> Signed-off-by: Junio C Hamano <>
Diffstat (limited to 'shallow.c')
1 files changed, 7 insertions, 0 deletions
diff --git a/shallow.c b/shallow.c
index 02fdbfc..ce45297 100644
--- a/shallow.c
+++ b/shallow.c
@@ -43,6 +43,13 @@ int register_shallow(struct repository *r, const struct object_id *oid)
int is_repository_shallow(struct repository *r)
+ /*
+ * NEEDSWORK: This function updates
+ * r->parsed_objects->{is_shallow,shallow_stat} as a side effect but
+ * there is no corresponding function to clear them when the shallow
+ * file is updated.
+ */
FILE *fp;
char buf[1024];
const char *path = r->parsed_objects->alternate_shallow_file;