Support >1 path in Gitlab::Git::Repository#log

This is analogous to `git log -- foo bar baz`, but not the same as
`Gitlab::Git::Repository#log(path: 'foo bar baz')`, which would run `git
log -- 'foo bar baz'`.

lib/gitlab/git/repository.rb

@@ -346,7 +346,12 @@ module Gitlab
         cmd << "--after=#{options[:after].iso8601}" if options[:after]
         cmd << "--before=#{options[:before].iso8601}" if options[:before]
         cmd << sha
-        cmd += %W[-- #{options[:path]}] if options[:path].present?
+
+        # :path can be a string or an array of strings
+        if options[:path].present?
+          cmd << '--'
+          cmd += Array(options[:path])
+        end
 
         raw_output = IO.popen(cmd) { |io| io.read }
         lines = offset_in_ruby ? raw_output.lines.drop(offset) : raw_output.lines

spec/lib/gitlab/git/repository_spec.rb

@@ -771,8 +771,8 @@ describe Gitlab::Git::Repository, seed_helper: true do
         commits = repository.log(options)
 
         expect(commits.size).to be > 0
-        satisfy do
-          commits.all? { |commit| commit.created_at >= options[:after] }
+        expect(commits).to satisfy do |commits|
+          commits.all? { |commit| commit.time >= options[:after] }
         end
       end
     end
@@ -784,8 +784,27 @@ describe Gitlab::Git::Repository, seed_helper: true do
         commits = repository.log(options)
 
         expect(commits.size).to be > 0
-        satisfy do
-          commits.all? { |commit| commit.created_at <= options[:before] }
+        expect(commits).to satisfy do |commits|
+          commits.all? { |commit| commit.time <= options[:before] }
+        end
+      end
+    end
+
+    context 'when multiple paths are provided' do
+      let(:options) { { ref: 'master', path: ['PROCESS.md', 'README.md'] } }
+
+      def commit_files(commit)
+        commit.diff(commit.parent_ids.first).deltas.flat_map do |delta|
+          [delta.old_file[:path], delta.new_file[:path]].uniq.compact
+        end
+      end
+
+      it 'only returns commits matching at least one path' do
+        commits = repository.log(options)
+
+        expect(commits.size).to be > 0
+        expect(commits).to satisfy do |commits|
+          commits.none? { |commit| (commit_files(commit) & options[:path]).empty? }
         end
       end
     end