Fix diff of requirements.txt file by not matching newlines as part of package names

changelogs/unreleased/dm-dependency-linker-newlines.yml

@@ -0,0 +1,5 @@
+---
+title: Fix diff of requirements.txt file by not matching newlines as part of package
+  names
+merge_request:
+author:

lib/gitlab/dependency_linker/base_linker.rb

@@ -52,7 +52,7 @@ module Gitlab
       #   # Will link `user/repo` in `github: "user/repo"` or `:github => "user/repo"`
       def link_regex(regex, &url_proc)
         highlighted_lines.map!.with_index do |rich_line, i|
-          marker = StringRegexMarker.new(plain_lines[i], rich_line.html_safe)
+          marker = StringRegexMarker.new(plain_lines[i].chomp, rich_line.html_safe)
 
           marker.mark(regex, group: :name) do |text, left:, right:|
             url = yield(text)

spec/lib/gitlab/dependency_linker/requirements_txt_linker_spec.rb

@@ -87,5 +87,9 @@ describe Gitlab::DependencyLinker::RequirementsTxtLinker, lib: true do
     it 'links URLs' do
       expect(subject).to include(link('http://wxpython.org/Phoenix/snapshot-builds/wxPython_Phoenix-3.0.3.dev1820+49a8884-cp34-none-win_amd64.whl', 'http://wxpython.org/Phoenix/snapshot-builds/wxPython_Phoenix-3.0.3.dev1820+49a8884-cp34-none-win_amd64.whl'))
     end
+
+    it 'does not contain link with a newline as package name' do
+      expect(subject).not_to include(link("\n", "https://pypi.python.org/pypi/\n"))
+    end
   end
 end