Integration test highlighting failure in shallow clone with submodule

Summary:
When shallow cloning a repo from Mononoke Git, we fetch all the objects from the root trees of the boundary commits. Before deciding to include them in the packfile, we filter out the ones specified by the filter criteria. One of the filter criteria is the size.

For most entries in the Git Tree, the size constraint makes sense. As long as the entry is a blob or a tree, we look at the size to decide if it should be included or not. However, when the entry is a submodule, the concept of size makes sense. The current version of the code doesn't make an explicit bypass for submodule entry but instead tries to fetch its size and fails. This integration test highlights that problem

Differential Revision: D71734349

fbshipit-source-id: 6e310cfba3096e88a8afad6785f9904d3dec5329

Author: RajivTS

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

@@ -0,0 +1,80 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+#
+# This software may be used and distributed according to the terms of the
+# GNU General Public License found in the LICENSE file in the root
+# directory of this source tree.
+
+  $ . "${TEST_FIXTURES}/library.sh"
+Disable Mercurial types as they do not support git submodules
+  $ DISABLED_DERIVED_DATA="filenodes hgchangesets hg_augmented_manifests" setup_common_config blob_files
+  $ GIT_REPO_ORIGIN="${TESTTMP}/origin/repo-git"
+  $ GIT_REPO_SUBMODULE="${TESTTMP}/origin/repo-submodule"
+  $ GIT_REPO="${TESTTMP}/repo-git"
+
+# Setup submodule git repository
+  $ mkdir -p "$GIT_REPO_SUBMODULE"
+  $ cd "$GIT_REPO_SUBMODULE"
+  $ git init -q
+  $ echo "this is submodule file1" > sub_file1
+  $ git add sub_file1
+  $ git commit -q -am "Add submodule file1"
+  $ echo "this is submodule file2" > sub_file2
+  $ git add sub_file2
+  $ git commit -q -am "Add submodule file2"
+
+# Setup git repository
+  $ mkdir -p "$GIT_REPO_ORIGIN"
+  $ cd "$GIT_REPO_ORIGIN"
+  $ git init -q
+# Add few regular commits
+  $ echo "this is file1" > file1
+  $ git add file1
+  $ git commit -qam "Add file1"
+  $ git tag -a -m "new tag" first_tag
+  $ echo "this is file2" > file2
+  $ git add file2
+  $ git commit -qam "Add file2"
+  $ echo "this is file3" > file3
+  $ git add file3
+  $ git commit -qam "Add file3"
+  $ git tag -a empty_tag -m ""
+# Add a submodule in this repository
+  $ git submodule add "$GIT_REPO_SUBMODULE"
+  Cloning into '$TESTTMP/origin/repo-git/repo-submodule'...
+  done.
+  $ git add .
+  $ git commit -q -am "Add a new submodule"
+  $ cd "$TESTTMP"
+  $ git clone "$GIT_REPO_ORIGIN"
+  Cloning into 'repo-git'...
+  done.
+
+# Import the repo into Mononoke
+  $ cd "$TESTTMP"
+  $ quiet gitimport "$GIT_REPO_ORIGIN" --generate-bookmarks full-repo
+
+# Start up the Mononoke Git Service
+  $ mononoke_git_service
+
+# Perform a shallow clone of the repo with depth = 2 and list the commits. This should work because the submodule is not
+# present at this depth
+  $ cd "$TESTTMP"
+  $ quiet git_client clone $MONONOKE_GIT_SERVICE_BASE_URL/$REPONAME.git --depth=2
+  $ rm -rf $REPONAME
+
+# 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]