Merge branch 'fix-backslashes-inline-diff' into 'master'

Fix bug where backslashes in inline diffs could be dropped

This MR fixes a bug in inline diff generation causing backslashes to be dropped. For example, the input:

```
input.to_s.sub(/[\r\n].+/,'').sub(/\\[rn].+/, '').strip
```

The second backslash is dropped in the second `sub` statement:

![image](https://gitlab.com/gitlab-org/gitlab-ce/uploads/16e513894f7ecda1b111fe7d43e7f388/image.png)

With this fix, it looks like:

![image](https://gitlab.com/gitlab-org/gitlab-ce/uploads/90fd635a937a68f1b2403740ebc75e3a/image.png)

Closes #2253

See merge request !1143

1 files changed, 39 insertions, 0 deletions

diff --git a/spec/lib/gitlab/diff/inline_diff_spec.rb b/spec/lib/gitlab/diff/inline_diff_spec.rb
new file mode 100644
index 00000000000..2e0a05088cc
--- /dev/null
+++ b/spec/lib/gitlab/diff/inline_diff_spec.rb
@@ -0,0 +1,39 @@
+require 'spec_helper'
+
+describe Gitlab::InlineDiff do
+  describe '#processing' do
+    let(:diff) do
+      <<eos
+--- a/test.rb
++++ b/test.rb
+@@ -1,6 +1,6 @@
+ class Test
+   def cleanup_string(input)
+     return nil if input.nil?
+-    input.sub(/[\\r\\n].+/,'').sub(/\\\\[rn].+/, '').strip
++    input.to_s.sub(/[\\r\\n].+/,'').sub(/\\\\[rn].+/, '').strip
+   end
+ end
+eos
+    end
+
+    let(:expected) do
+      ["--- a/test.rb\n",
+       "+++ b/test.rb\n",
+       "@@ -1,6 +1,6 @@\n",
+       " class Test\n",
+       "   def cleanup_string(input)\n",
+       "     return nil if input.nil?\n",
+       "-    input.#!idiff-start!##!idiff-finish!#sub(/[\\r\\n].+/,'').sub(/\\\\[rn].+/, '').strip\n",
+       "+    input.#!idiff-start!#to_s.#!idiff-finish!#sub(/[\\r\\n].+/,'').sub(/\\\\[rn].+/, '').strip\n",
+       "   end\n",
+       " end\n"]
+    end
+
+    let(:subject) { Gitlab::InlineDiff.processing(diff.lines) }
+
+    it 'should retain backslashes' do
+      expect(subject).to eq(expected)
+    end
+  end
+end