add support for curly brackets with the --pattern option, fixes rspec…

…#868

features/configuration/pattern.feature

@@ -28,3 +28,11 @@ Feature: pattern
   Scenario: the --pattern flag makes RSpec run files matching the specified pattern and ignore the default pattern
    When I run `rspec -P "**/*_test.rb"`
    Then the output should contain "1 example, 0 failures"
+
+  Scenario: the --pattern flag can be used to pass in multiple patterns, separated by comma
+   When I run `rspec -P "**/*_test.rb,**/*_spec.rb"`
+   Then the output should contain "3 examples, 0 failures"
+
+  Scenario: the --pattern flag accepts shell style glob unions
+   When I run `rspec -P "**/*_{test,spec}.rb"`
+   Then the output should contain "3 examples, 0 failures"

lib/rspec/core/configuration.rb

@@ -977,17 +977,16 @@ def order_groups_and_examples(&block)
     private
 
       def get_files_to_run(paths)
-        patterns = pattern.split(",")
         paths.map do |path|
           path = path.gsub(File::ALT_SEPARATOR, File::SEPARATOR) if File::ALT_SEPARATOR
-          File.directory?(path) ? gather_directories(path, patterns) : extract_location(path)
+          File.directory?(path) ? gather_directories(path) : extract_location(path)
         end.flatten.sort
       end
 
-      def gather_directories(path, patterns)
-        patterns.map do |pattern|
-          pattern =~ /^#{path}/ ? Dir[pattern.strip].sort : Dir["#{path}/{#{pattern.strip}}"].sort
-        end
+      def gather_directories(path)
+        stripped = "{#{pattern.strip}}"
+        files    = pattern.start_with?(path) ? Dir[stripped] : Dir["#{path}/#{stripped}"]
+        files.sort
       end
 
       def extract_location(path)