Pass fallback_diff_refs to Diff::File instead of using view helpers

3 files changed, 57 insertions, 31 deletions

diff --git a/lib/gitlab/diff/file.rb b/lib/gitlab/diff/file.rb
index a812d549397..2aef7fdaa35 100644
--- a/lib/gitlab/diff/file.rb
+++ b/lib/gitlab/diff/file.rb
@@ -1,16 +1,17 @@
 module Gitlab
   module Diff
     class File
-      attr_reader :diff, :repository, :diff_refs
+      attr_reader :diff, :repository, :diff_refs, :fallback_diff_refs
 
       delegate :new_file?, :deleted_file?, :renamed_file?,
         :old_path, :new_path, :a_mode, :b_mode, :mode_changed?,
         :submodule?, :too_large?, :collapsed?, to: :diff, prefix: false
 
-      def initialize(diff, repository:, diff_refs: nil)
+      def initialize(diff, repository:, diff_refs: nil, fallback_diff_refs: nil)
         @diff = diff
         @repository = repository
         @diff_refs = diff_refs
+        @fallback_diff_refs = fallback_diff_refs
       end
 
       def position(line)
@@ -49,24 +50,60 @@ module Gitlab
         line_code(line) if line
       end
 
+      def old_sha
+        diff_refs&.base_sha
+      end
+
+      def new_sha
+        diff_refs&.head_sha
+      end
+
+      def content_sha
+        return old_content_sha if deleted_file?
+        return @content_sha if defined?(@content_sha)
+
+        refs = diff_refs || fallback_diff_refs
+        @content_sha = refs&.head_sha
+      end
+
       def content_commit
-        return unless diff_refs
+        return @content_commit if defined?(@content_commit)
+
+        sha = content_sha
+        @content_commit = repository.commit(sha) if sha
+      end
+
+      def old_content_sha
+        return if new_file?
+        return @old_content_sha if defined?(@old_content_sha)
 
-        repository.commit(deleted_file? ? old_sha : new_sha)
+        refs = diff_refs || fallback_diff_refs
+        @old_content_sha = refs&.base_sha
       end
 
       def old_content_commit
-        return unless diff_refs
+        return @old_content_commit if defined?(@old_content_commit)
 
-        repository.commit(old_sha)
+        sha = old_content_sha
+        @old_content_commit = repository.commit(sha) if sha
       end
 
-      def old_sha
-        diff_refs.try(:base_sha)
+      def blob
+        return @blob if defined?(@blob)
+
+        sha = content_sha
+        return @blob = nil unless sha
+
+        repository.blob_at(sha, file_path)
       end
 
-      def new_sha
-        diff_refs.try(:head_sha)
+      def old_blob
+        return @old_blob if defined?(@old_blob)
+
+        sha = old_content_sha
+        return @old_blob = nil unless sha
+
+        @old_blob = repository.blob_at(sha, old_path)
       end
 
       attr_writer :highlighted_diff_lines
@@ -113,19 +150,6 @@ module Gitlab
         diff_lines.count(&:removed?)
       end
 
-      def old_blob(commit = old_content_commit)
-        return unless commit
-        return if new_file?
-
-        repository.blob_at(commit.id, old_path)
-      end
-
-      def blob(commit = content_commit)
-        return unless commit
-
-        repository.blob_at(commit.id, file_path)
-      end
-
       def file_identifier
         "#{file_path}-#{new_file?}-#{deleted_file?}-#{renamed_file?}"
       end
diff --git a/lib/gitlab/diff/file_collection/base.rb b/lib/gitlab/diff/file_collection/base.rb
index 2b9fc65b985..7330f3377e1 100644
--- a/lib/gitlab/diff/file_collection/base.rb
+++ b/lib/gitlab/diff/file_collection/base.rb
@@ -2,7 +2,7 @@ module Gitlab
   module Diff
     module FileCollection
       class Base
-        attr_reader :project, :diff_options, :diff_view, :diff_refs
+        attr_reader :project, :diff_options, :diff_view, :diff_refs, :fallback_diff_refs
 
         delegate :count, :size, :real_size, to: :diff_files
 
@@ -10,14 +10,15 @@ module Gitlab
           ::Commit.max_diff_options.merge(ignore_whitespace_change: false, no_collapse: false)
         end
 
-        def initialize(diffable, project:, diff_options: nil, diff_refs: nil)
+        def initialize(diffable, project:, diff_options: nil, diff_refs: nil, fallback_diff_refs: nil)
           diff_options = self.class.default_options.merge(diff_options || {})
 
-          @diffable     = diffable
-          @diffs        = diffable.raw_diffs(diff_options)
-          @project      = project
+          @diffable = diffable
+          @diffs = diffable.raw_diffs(diff_options)
+          @project = project
           @diff_options = diff_options
-          @diff_refs    = diff_refs
+          @diff_refs = diff_refs
+          @fallback_diff_refs = fallback_diff_refs
         end
 
         def diff_files
@@ -27,7 +28,7 @@ module Gitlab
         private
 
         def decorate_diff!(diff)
-          Gitlab::Diff::File.new(diff, repository: project.repository, diff_refs: diff_refs)
+          Gitlab::Diff::File.new(diff, repository: project.repository, diff_refs: diff_refs, fallback_diff_refs: fallback_diff_refs)
         end
       end
     end
diff --git a/lib/gitlab/diff/file_collection/merge_request_diff.rb b/lib/gitlab/diff/file_collection/merge_request_diff.rb
index 0bd226ef050..9a58b500a2c 100644
--- a/lib/gitlab/diff/file_collection/merge_request_diff.rb
+++ b/lib/gitlab/diff/file_collection/merge_request_diff.rb
@@ -8,7 +8,8 @@ module Gitlab
           super(merge_request_diff,
             project: merge_request_diff.project,
             diff_options: diff_options,
-            diff_refs: merge_request_diff.diff_refs)
+            diff_refs: merge_request_diff.diff_refs,
+            fallback_diff_refs: merge_request_diff.fallback_diff_refs)
         end
 
         def diff_files