Add start_sha to commits API

When passing start_branch on committing from the WebIDE, it's possible
that the branch has changed since editing started, which results in the
change being applied on top of the latest commit in the branch and
overwriting the new changes.

By passing the start_sha instead we can make sure that the change is
applied on top of the commit which the user started editing from.

1 files changed, 1 insertions, 1 deletions

diff --git a/spec/services/submodules/update_service_spec.rb b/spec/services/submodules/update_service_spec.rb
index cf92350c1b2..47b31d4bcbf 100644
--- a/spec/services/submodules/update_service_spec.rb
+++ b/spec/services/submodules/update_service_spec.rb
@@ -142,7 +142,7 @@ describe Submodules::UpdateService do
             let(:branch_name) { nil }
 
             it_behaves_like 'returns error result' do
-              let(:error_message) { 'You can only create or edit files when you are on a branch' }
+              let(:error_message) { 'Invalid parameters' }
             end
           end