Fix 500 error when trying to resolve non-ASCII conflicts in editor

When we added caching, this meant that calling `can_be_resolved_in_ui?` didn't
always call `lines`, which meant that we didn't get the benefit of the
side-effect from that, where it forced the conflict data itself to UTF-8.

To fix that, make this explicit by separating the `raw_content` (any encoding)
from the `content` (which is either UTF-8, or an exception is raised).

2 files changed, 50 insertions, 7 deletions

diff --git a/spec/lib/gitlab/git/conflict/file_spec.rb b/spec/lib/gitlab/git/conflict/file_spec.rb
new file mode 100644
index 00000000000..afed6c32af6
--- /dev/null
+++ b/spec/lib/gitlab/git/conflict/file_spec.rb
@@ -0,0 +1,50 @@
+# coding: utf-8
+require 'spec_helper'
+
+describe Gitlab::Git::Conflict::File do
+  let(:conflict) { { theirs: { path: 'foo', mode: 33188 }, ours: { path: 'foo', mode: 33188 } } }
+  let(:invalid_content) { described_class.new(nil, nil, conflict, "a\xC4\xFC".force_encoding(Encoding::ASCII_8BIT)) }
+  let(:valid_content) { described_class.new(nil, nil, conflict, "Espa\xC3\xB1a".force_encoding(Encoding::ASCII_8BIT)) }
+
+  describe '#lines' do
+    context 'when the content contains non-UTF-8 characters' do
+      it 'raises UnsupportedEncoding' do
+        expect { invalid_content.lines }
+          .to raise_error(described_class::UnsupportedEncoding)
+      end
+    end
+
+    context 'when the content can be converted to UTF-8' do
+      it 'sets lines to the lines' do
+        expect(valid_content.lines).to eq([{
+                                             full_line: 'España',
+                                             type: nil,
+                                             line_obj_index: 0,
+                                             line_old: 1,
+                                             line_new: 1
+                                           }])
+      end
+
+      it 'sets the type to text' do
+        expect(valid_content.type).to eq('text')
+      end
+    end
+  end
+
+  describe '#content' do
+    context 'when the content contains non-UTF-8 characters' do
+      it 'raises UnsupportedEncoding' do
+        expect { invalid_content.content }
+          .to raise_error(described_class::UnsupportedEncoding)
+      end
+    end
+
+    context 'when the content can be converted to UTF-8' do
+      it 'returns a valid UTF-8 string' do
+        expect(valid_content.content).to eq('España')
+        expect(valid_content.content).to be_valid_encoding
+        expect(valid_content.content.encoding).to eq(Encoding::UTF_8)
+      end
+    end
+  end
+end
diff --git a/spec/lib/gitlab/git/conflict/parser_spec.rb b/spec/lib/gitlab/git/conflict/parser_spec.rb
index 7b035a381f1..29a1702a1c6 100644
--- a/spec/lib/gitlab/git/conflict/parser_spec.rb
+++ b/spec/lib/gitlab/git/conflict/parser_spec.rb
@@ -212,13 +212,6 @@ CONFLICT
             .not_to raise_error
         end
       end
-
-      context 'when the file contains non-UTF-8 characters' do
-        it 'raises UnsupportedEncoding' do
-          expect { parse_text("a\xC4\xFC".force_encoding(Encoding::ASCII_8BIT)) }
-            .to raise_error(Gitlab::Git::Conflict::Parser::UnsupportedEncoding)
-        end
-      end
     end
   end
 end