Merge branch 'fix-diff-highlighting' into 'master'

Fix diff syntax highlighting

### What does this MR do?

This MR fixes a syntax highlighting issue that that manifested itself when a user tried the following:

```
+aaa
+bbb
 ccc
```

However, a regression in 0abe98f0 caused the last line to be put on the second to last line:

![image](https://gitlab.com/stanhu/gitlab-ce/uploads/a16515499d5e3fd9737370d89c73f671/image.png)

Instead of this:

![image](https://gitlab.com/gitlab-org/gitlab-ce/uploads/59eca6efd4c290aa633b9fb54c98a70e/image.png)

This bug occurred because of some error in the logic of handling new lines in the content. Refactored HTML parser to avoid duplication of newline parsing.

### What are the relevant issue numbers?

Closes #2235

See merge request !1126

2 files changed, 17 insertions, 1 deletions

diff --git a/spec/helpers/blob_helper_spec.rb b/spec/helpers/blob_helper_spec.rb
index 76009c36099..b8bba36439a 100644
--- a/spec/helpers/blob_helper_spec.rb
+++ b/spec/helpers/blob_helper_spec.rb
@@ -47,5 +47,21 @@ describe BlobHelper do
       expect(lines[1].text).to eq('        This is line 2.')
       expect(lines[2].text).to eq('        """')
     end
+
+    context 'diff highlighting' do
+      let(:blob_name) { 'test.diff' }
+      let(:blob_content) { "+aaa\n+bbb\n- ccc\n ddd\n"}
+      let(:expected) do
+        %q(<span id="LC1" class="line"><span class="gi">+aaa</span></span>
+<span id="LC2" class="line"><span class="gi">+bbb</span></span>
+<span id="LC3" class="line"><span class="gd">- ccc</span></span>
+<span id="LC4" class="line"> ddd</span>)
+      end
+
+      it 'should highlight each line properly' do
+        result = highlight(blob_name, blob_content, nowrap: true, continue: false)
+        expect(result).to eq(expected)
+      end
+    end
   end
 end
diff --git a/spec/helpers/events_helper_spec.rb b/spec/helpers/events_helper_spec.rb
index b392371deb4..da58ab98462 100644
--- a/spec/helpers/events_helper_spec.rb
+++ b/spec/helpers/events_helper_spec.rb
@@ -58,7 +58,7 @@ describe EventsHelper do
     expected = '<pre class="code highlight white ruby">' \
       "<code><span class=\"k\">def</span> <span class=\"nf\">test</span>\n" \
       "  <span class=\"s1\">\'hello world\'</span>\n" \
-      "<span class=\"k\">end</span>\n" \
+      "<span class=\"k\">end</span>" \
       '</code></pre>'
     expect(event_note(input)).to eq(expected)
   end