Make fail_under fail if there is no coverage data.

2 files changed, 10 insertions, 1 deletions

diff --git a/coverage/results.py b/coverage/results.py
index 7b621c18..11b86424 100644
--- a/coverage/results.py
+++ b/coverage/results.py
@@ -211,7 +211,7 @@ class Numbers(object):
             numerator, denominator = self.ratio_covered
             pc_cov = (100.0 * numerator) / denominator
         else:
-            pc_cov = 100.0
+            pc_cov = 0.0
         return pc_cov
 
     @property
diff --git a/tests/test_process.py b/tests/test_process.py
index 1ae8e922..24da57a6 100644
--- a/tests/test_process.py
+++ b/tests/test_process.py
@@ -703,6 +703,15 @@ class FailUnderTest(CoverageTest):
         st, _ = self.run_command_status("coverage report")
         self.assertEqual(st, 2)
 
+class FailUnderNoDataTest(CoverageTest):
+    def test_fail_under_in_config_no_data(self):
+        self.make_file(".coveragerc", "[report]\nfail_under = 99\n")
+        if os.path.exists('.coverage'):
+            os.remove('.coverage')
+        st, _ = self.run_command_status("coverage report")
+        print _
+        self.assertEqual(st, 2)
+
 
 def possible_pth_dirs():
     """Produce a sequence of directories for trying to write .pth files."""