Add missing branch descriptions for handling exceptions

2 files changed, 23 insertions, 2 deletions

diff --git a/coverage/parser.py b/coverage/parser.py
index 715ab156..aa7693f8 100644
--- a/coverage/parser.py
+++ b/coverage/parser.py
@@ -786,14 +786,15 @@ class AstArcAnalyzer(object):
 
         handler_exits = set()
 
-        last_handler_start = None
         if node.handlers:
+            last_handler_start = None
             for handler_node in node.handlers:
                 handler_start = self.line_for_node(handler_node)
                 if last_handler_start is not None:
                     self.arcs.add((last_handler_start, handler_start))
                 last_handler_start = handler_start
-                handler_exits |= self.add_body_arcs(handler_node.body, from_start=ArcStart(handler_start))
+                from_start = ArcStart(handler_start, cause="the exception caught by line {lineno} didn't happen")
+                handler_exits |= self.add_body_arcs(handler_node.body, from_start=from_start)
 
         if node.orelse:
             exits = self.add_body_arcs(node.orelse, prev_starts=exits)
diff --git a/tests/test_parser.py b/tests/test_parser.py
index 53a514e0..d9781343 100644
--- a/tests/test_parser.py
+++ b/tests/test_parser.py
@@ -250,6 +250,26 @@ class ParserMissingArcDescriptionTest(CoverageTest):
             "line 5 didn't run the set comprehension on line 5"
         )
 
+    def test_missing_arc_descriptions_for_exceptions(self):
+        text = textwrap.dedent(u"""\
+            try:
+                pass
+            except ZeroDivideError:
+                print("whoops")
+            except ValueError:
+                print("yikes")
+            """)
+        parser = PythonParser(text=text)
+        parser.parse_source()
+        self.assertEqual(
+            parser.missing_arc_description(3, 4),
+            "line 3 didn't jump to line 4, because the exception caught by line 3 didn't happen"
+        )
+        self.assertEqual(
+            parser.missing_arc_description(5, 6),
+            "line 5 didn't jump to line 6, because the exception caught by line 5 didn't happen"
+        )
+
 
 class ParserFileTest(CoverageTest):
     """Tests for coverage.py's code parsing from files."""