Bug 1081970 - Gracefully handle interrupts when running test suite. r=dburns

--HG--
extra : commitid : 9JQBIHQNMoV
extra : rebase_source : 9db8ccab407a78095fb67ee61e574d301364d416

testing/marionette/client/marionette/runner/base.py

@@ -808,6 +808,8 @@ setReq.onerror = function() {
                                  message=test['disabled'])
             self.todo += 1
 
+        interrupted = None
+        try:
             counter = self.repeat
             while counter >=0:
                 round = self.repeat - counter
@@ -815,7 +817,23 @@ setReq.onerror = function() {
                     self.logger.info('\nREPEAT %d\n-------' % round)
                 self.run_test_sets()
                 counter -= 1
+        except KeyboardInterrupt:
+            # in case of KeyboardInterrupt during the test execution
+            # we want to display current test results.
+            # so we keep the exception to raise it later.
+            interrupted = sys.exc_info()
+        try:
+            self._print_summary(tests)
+        except:
+            # raise only the exception if we were not interrupted
+            if not interrupted:
+                raise
+        finally:
+            # reraise previous interruption now
+            if interrupted:
+                raise interrupted[0], interrupted[1], interrupted[2]
 
+    def _print_summary(self, tests):
         self.logger.info('\nSUMMARY\n-------')
         self.logger.info('passed: %d' % self.passed)
         if self.unexpected_successes == 0: