Don't attempt to build the cache if the project repo is emptysh-handle-empty-import

Attempting to import an empty repo causes `Repository#build_cache`
to fail with a `nil Exception.

3 files changed, 13 insertions, 0 deletions

diff --git a/app/models/repository.rb b/app/models/repository.rb
index 063dc74021d..c01895b75e4 100644
--- a/app/models/repository.rb
+++ b/app/models/repository.rb
@@ -333,6 +333,8 @@ class Repository
   end
 
   def build_cache
+    return if empty?
+
     (cache_keys + cache_keys_for_branches_and_tags).each do |key|
       unless cache.exist?(key)
         send(key)
diff --git a/changelogs/unreleased/sh-handle-empty-import.yml b/changelogs/unreleased/sh-handle-empty-import.yml
new file mode 100644
index 00000000000..500c573d587
--- /dev/null
+++ b/changelogs/unreleased/sh-handle-empty-import.yml
@@ -0,0 +1,4 @@
+---
+title: Don't attempt to build the cache if the project repo is empty
+merge_request: 
+author: 
diff --git a/spec/models/repository_spec.rb b/spec/models/repository_spec.rb
index fe26b4ac18c..b1dcb17f2d8 100644
--- a/spec/models/repository_spec.rb
+++ b/spec/models/repository_spec.rb
@@ -1491,6 +1491,13 @@ describe Repository, models: true do
 
       repository.build_cache
     end
+
+    it 'does not build cache for an empty repo' do
+      empty_project = create(:project_empty_repo)
+      expect(empty_project.repository.send(:cache)).not_to receive(:exist?)
+
+      empty_project.repository.build_cache
+    end
   end
 
   describe "#keep_around" do