Add cannot_be_merged_recheck merge_status

First, transitions between can_be_merged & cannot_be_merged are removed,
as they are currently blocked in `check_if_can_be_merged`.
`can_be_merge` always returns to `unchecked` first,
before it can transition to `cannot_be_merged` (and vice versa).

We want to avoid repeated notification triggered by repeated transition
between `cannot_be_merged` & `unchecked`.

So we added `cannot_be_merged_recheck` state, similar to `unchecked`,
but as a mean to remember it’s from cannot_be_merged.

See https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/18042/#note_65945407

Since `unchecked` and `cannot_be_merged_recheck` both mean
“we are in the middle of checking if it is mergeable”,
quite often we need to see if merge_status is in either one of them,
so `check_state?` is added to achieve this.

1 files changed, 1 insertions, 1 deletions

diff --git a/spec/features/merge_request/user_resolves_conflicts_spec.rb b/spec/features/merge_request/user_resolves_conflicts_spec.rb
index 19995559fae..ac3c734599c 100644
--- a/spec/features/merge_request/user_resolves_conflicts_spec.rb
+++ b/spec/features/merge_request/user_resolves_conflicts_spec.rb
@@ -10,7 +10,7 @@ describe 'Merge request > User resolves conflicts', :js do
   end
 
   def create_merge_request(source_branch)
-    create(:merge_request, source_branch: source_branch, target_branch: 'conflict-start', source_project: project) do |mr|
+    create(:merge_request, source_branch: source_branch, target_branch: 'conflict-start', source_project: project, merge_status: :unchecked) do |mr|
       mr.mark_as_unmergeable
     end
   end