Merge branch '35368-fix-gcovr-regexp-matching' into 'master'

Fix the gcovr coverage regex by removing line separators before scanning

Closes #35368

See merge request !13025

lib/gitlab/ci/trace/stream.rb

@@ -74,6 +74,7 @@ module Gitlab
           match = ""
           reverse_line do |line|
+            line.chomp!
             matches = regex.scan(line)
             next unless matches.is_a?(Array)
             next if matches.empty?

spec/lib/gitlab/ci/trace/stream_spec.rb

@@ -300,5 +300,12 @@ describe Gitlab::Ci::Trace::Stream do
       include_examples 'malicious regexp'
     end
+
+    context 'multi-line data with rooted regexp' do
+      let(:data) { "\n65%\n" }
+      let(:regex) { '^(\d+)\%$' }
+
+      it { is_expected.to eq('65') }
+    end
   end
 end