Fix bug in implementation of shallow in Mononoke Git server

Summary: As demonstrated in the previous diff, shallow clone of a submoduled repo can fail depending on the shallow boundary. This diff adds an explicit check before applying the size filter for the shallow boundary. If the object is in object is a submodule, do not perform the size check.

Differential Revision: D71735051

fbshipit-source-id: 5dff655e87b05b82fb3b3909ee47bdf991922067

Author: RajivTS

eden/mononoke/git/git_types/src/tree.rs

@@ -144,6 +144,9 @@ impl GitLeaf {
     }
 
     pub(crate) async fn size(&self, ctx: &CoreContext, blobstore: &impl Blobstore) -> Result<u64> {
+        if self.is_submodule() {
+            anyhow::bail!("Fetching size of GitLeaf item that is a submodule is not supported");
+        }
         let key = GitSha1::from_object_id(&self.0)?.into();
         let metadata = filestore::get_metadata(blobstore, ctx, &key)
             .await?

eden/mononoke/git/protocol/src/generator.rs

@@ -106,7 +106,11 @@ async fn boundary_trees_and_blobs(
                 let objects = root_tree.list_all_entries((*ctx).clone(), blobstore.clone()).try_filter_map(|(path, entry)|{
                     cloned!(ctx, blobstore, filter);
                     async move {
-                        let size = entry.size(&ctx, &blobstore).await?;
+                        // If the entry is a submodule, then the concept of size does not apply. Assume 0 since it will be ignored anyway
+                        let size = match entry.is_submodule() {
+                            true => 0,
+                            false => entry.size(&ctx, &blobstore).await?
+                        };
                         let kind = entry.kind();
                         let oid = entry.oid();
                         // If the entry corresponds to a submodules (and shows up as a commit), then we ignore it
@@ -121,7 +125,7 @@ async fn boundary_trees_and_blobs(
                 .await
                 .with_context(|| {
                     format!(
-                        "Error while listing all entries from GitTree for changeset {changeset_id:?}",
+                        "Error while listing all entries from GitTree for changeset {changeset_id:?} and root tree {root_tree:?}",
                     )
                 })?;
                 Ok(objects)

eden/mononoke/tests/integration/mononoke_git_server/test-mononoke-git-server-shallow-clone-with-submodule.t

@@ -64,17 +64,4 @@ Disable Mercurial types as they do not support git submodules
 
 # Perform a shallow clone of the repo with depth = 1 and list the commits. This should fail because we try to fetch the
 # size of the submodule
-  $ git_client clone $MONONOKE_GIT_SERVICE_BASE_URL/$REPONAME.git --depth=1
-  Cloning into 'repo'...
-  remote: Converting HAVE Git commits to Bonsais        
-  remote: Converting WANT Git commits to Bonsais        
-  remote: Collecting Bonsai commits to send to client        
-  remote: Counting number of objects to be sent in packfile        
-  remote: Error while calculating object count during fetch
-  
-  Caused by:
-      0: Error while listing all entries from GitTree for changeset ChangesetId(Blake2(*)) (glob)
-      1: No metadata for de0c53cc213a98b1382aec1dcbcb01bf088273e4
-  fatal: early EOF
-  fatal: fetch-pack: invalid index-pack output
-  [128]
+  $ quiet git_client clone $MONONOKE_GIT_SERVICE_BASE_URL/$REPONAME.git --depth=1