Merge branch '40463-ee-compatibility-check-job-fails-unexpectedly' into 'master'

Resolve "EE Compatibility Check Job Fails Unexpectedly"

Closes #40463

See merge request gitlab-org/gitlab-ce!15555

lib/gitlab/ee_compat_check.rb

@@ -91,7 +91,7 @@ module Gitlab
 
       step(
         "Generating the patch against #{remote}/master in #{patch_path}",
-        %W[git diff --binary #{remote}/master...#{branch}]
+        %W[git diff --binary #{remote}/master...origin/#{branch}]
       ) do |output, status|
         throw(:halt_check, :ko) unless status.zero?
 
@@ -102,7 +102,7 @@ module Gitlab
     end
 
     def ce_branch_compat_check!
-      if check_patch(ce_patch_full_path, remote: 'canonical-ce').zero?
+      if check_patch(ce_patch_full_path).zero?
         puts applies_cleanly_msg(ce_branch)
         throw(:halt_check)
       end
@@ -129,7 +129,7 @@ module Gitlab
     end
 
     def ee_branch_compat_check!
-      unless check_patch(ee_patch_full_path, remote: 'canonical-ee').zero?
+      unless check_patch(ee_patch_full_path).zero?
         puts
         puts ee_branch_doesnt_apply_cleanly_msg
 
@@ -140,9 +140,9 @@ module Gitlab
       puts applies_cleanly_msg(ee_branch_found)
     end
 
-    def check_patch(patch_path, remote:)
+    def check_patch(patch_path)
       step("Checking out master", %w[git checkout master])
-      step("Resetting to latest master", %W[git reset --hard #{remote}/master])
+      step("Resetting to latest master", %w[git reset --hard canonical-ee/master])
       step(
         "Checking if #{patch_path} applies cleanly to EE/master",
         # Don't use --check here because it can result in a 0-exit status even
@@ -182,7 +182,7 @@ module Gitlab
     def merge_base_found?(master_remote:, branch:)
       step(
         "Finding merge base with #{master_remote}/master",
-        %W[git merge-base #{master_remote}/master #{branch}]
+        %W[git merge-base #{master_remote}/master origin/#{branch}]
       ) do |output, status|
         if status.zero?
           puts "Merge base was found: #{output}"