MAINT: Fix warningc context tests, uncover bug?

Author: bsipocz

numpy/testing/tests/test_utils.py

@@ -1294,17 +1294,23 @@ def test_clear_and_catch_warnings():
         warnings.simplefilter('ignore')
         warnings.warn('Some warning')
     assert_equal(my_mod.__warningregistry__, {})
-    # Without specified modules, don't clear warnings during context
+    # Without specified modules, don't clear warnings during context.
+    # catch_warnings doesn't make an entry for 'ignore'.
     with clear_and_catch_warnings():
         warnings.simplefilter('ignore')
         warnings.warn('Some warning')
-    assert_warn_len_equal(my_mod, 1)
+    assert_warn_len_equal(my_mod, 0)
+
+    # Manually adding two warnings to the registry:
+    my_mod.__warningregistry__ = {'warning1': 1,
+                                  'warning2': 2}
+
     # Confirm that specifying module keeps old warning, does not add new
     with clear_and_catch_warnings(modules=[my_mod]):
         warnings.simplefilter('ignore')
         warnings.warn('Another warning')
-    assert_warn_len_equal(my_mod, 1)
-    # Another warning, no module spec does add to warnings dict, except on
+    assert_warn_len_equal(my_mod, 2)
+    # Another warning, no module spec does add to warnings dict
     with clear_and_catch_warnings():
         warnings.simplefilter('ignore')
         warnings.warn('Another warning')
@@ -1350,11 +1356,15 @@ def warn(arr):
         warnings.warn('Some warning')
     assert_warn_len_equal(my_mod, 0)
 
+    # Manually adding two warnings to the registry:
+    my_mod.__warningregistry__ = {'warning1': 1,
+                                  'warning2': 2}
+
     # Without specified modules, don't clear warnings during context
     with suppress_warnings():
         warnings.simplefilter('ignore')
         warnings.warn('Some warning')
-    assert_warn_len_equal(my_mod, 1)
+    assert_warn_len_equal(my_mod, 2)
 
 
 def test_suppress_warnings_type():
@@ -1378,11 +1388,15 @@ def test_suppress_warnings_type():
         warnings.warn('Some warning')
     assert_warn_len_equal(my_mod, 0)
 
+    # Manually adding two warnings to the registry:
+    my_mod.__warningregistry__ = {'warning1': 1,
+                                  'warning2': 2}
+
     # Without specified modules, don't clear warnings during context
     with suppress_warnings():
         warnings.simplefilter('ignore')
         warnings.warn('Some warning')
-    assert_warn_len_equal(my_mod, 1)
+    assert_warn_len_equal(my_mod, 2)
 
 
 def test_suppress_warnings_decorate_no_record():