Don't track unhandled exception branches

3 files changed, 20 insertions, 29 deletions

diff --git a/CHANGES.rst b/CHANGES.rst
index 550a595c..709e1395 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -6,6 +6,14 @@ Change history for Coverage.py
 ==============================
 
 
+Unreleased
+----------
+
+- When running your program, execution can jump from an ``except X:`` line to
+  some other line when an exception other than ``X`` happens.  This jump is no
+  longer considered a branch when measuring branch coverage.
+
+
 Version 4.1b2 --- 2016-01-23 
 ----------------------------
 
diff --git a/coverage/parser.py b/coverage/parser.py
index 27c17438..17f1f0d5 100644
--- a/coverage/parser.py
+++ b/coverage/parser.py
@@ -631,13 +631,6 @@ class AstArcAnalyzer(object):
                     self.arcs.add((last_handler_start, handler_start))
                 last_handler_start = handler_start
                 handler_exits |= self.add_body_arcs(handler_node.body, from_line=handler_start)
-                if handler_node.type is None:
-                    # "except:" doesn't jump to subsequent handlers, or
-                    # "finally:".
-                    last_handler_start = None
-                    # Note that once we have `except:`, no further handlers
-                    # will ever be run.  We'll keep collecting them, and the
-                    # code will get marked as not run.
 
         if node.orelse:
             exits = self.add_body_arcs(node.orelse, prev_lines=exits)
@@ -653,11 +646,6 @@ class AstArcAnalyzer(object):
                 try_block.raise_from |          # or a `raise`,
                 try_block.return_from           # or a `return`.
             )
-            if last_handler_start is not None:
-                # If we had handlers, and we didn't have a bare `except:`
-                # handler, then the last handler jumps to the `finally` for the
-                # unhandled exceptions.
-                final_from.add(last_handler_start)
 
             exits = self.add_body_arcs(node.finalbody, prev_lines=final_from)
             if try_block.break_from:
@@ -668,11 +656,6 @@ class AstArcAnalyzer(object):
                 self.process_raise_exits(exits)
             if try_block.return_from:
                 self.process_return_exits(exits)
-        else:
-            # No final body: if there is an `except` handler without a
-            # catch-all, then exceptions can raise from there.
-            if last_handler_start is not None:
-                self.process_raise_exits([last_handler_start])
 
         return exits
 
diff --git a/tests/test_arcs.py b/tests/test_arcs.py
index 5c0d1e50..030b719d 100644
--- a/tests/test_arcs.py
+++ b/tests/test_arcs.py
@@ -704,8 +704,8 @@ class ExceptionArcTest(CoverageTest):
                 c = 9
             assert a == 3 and b == 1 and c == 9
             """,
-            arcz=".1 12 23 45 46 39 59 67 79 69 9A A.",
-            arcz_missing="45 59 46 67 79 69",
+            arcz=".1 12 23 45 46 39 59 67 79 9A A.",
+            arcz_missing="45 59 46 67 79",
         )
         self.check_coverage("""\
             a, b, c = 1, 1, 1
@@ -719,8 +719,8 @@ class ExceptionArcTest(CoverageTest):
                 c = 9
             assert a == 1 and b == 5 and c == 9
             """,
-            arcz=".1 12 23 45 46 69 39 59 67 79 9A A.",
-            arcz_missing="39 46 67 79 69",
+            arcz=".1 12 23 45 46 39 59 67 79 9A A.",
+            arcz_missing="39 46 67 79",
             arcz_unpredicted="34",
         )
         self.check_coverage("""\
@@ -735,8 +735,8 @@ class ExceptionArcTest(CoverageTest):
                 c = 9
             assert a == 7 and b == 1 and c == 9
             """,
-            arcz=".1 12 23 45 46 39 59 67 79 69 9A A.",
-            arcz_missing="39 45 59 69",
+            arcz=".1 12 23 45 46 39 59 67 79 9A A.",
+            arcz_missing="39 45 59",
             arcz_unpredicted="34",
         )
         self.check_coverage("""\
@@ -754,9 +754,9 @@ class ExceptionArcTest(CoverageTest):
                 pass
             assert a == 1 and b == 1 and c == 10
             """,
-            arcz=".1 12 23 34 4A 56 6A 57 78 8A 7A AD BC CD D.",
+            arcz=".1 12 23 34 4A 56 6A 57 78 8A AD BC CD D.",
             arcz_missing="4A 56 6A 78 8A AD",
-            arcz_unpredicted="45 AB",
+            arcz_unpredicted="45 7A AB",
         )
 
     def test_return_finally(self):
@@ -808,11 +808,11 @@ class ExceptionArcTest(CoverageTest):
             """,
             arcz=
                 ".1 1Q QR RS ST T. "
-                ".2 23 34 45 56 4O 6L 7L "
+                ".2 23 34 45 56 4O 6L "
                 "78 89 9A AL  8B BC CD DL  BE EF FG GL  EH HI IJ JL  HL "
                 "LO L4 L. LM "
                 "MN NO O.",
-            arcz_missing="6L 7L HL",
+            arcz_missing="6L HL",
             arcz_unpredicted="67",
         )
 
@@ -852,11 +852,11 @@ class ExceptionArcTest(CoverageTest):
             """,
             arcz=
                 ".1 1S ST TU UV V. "
-                ".2 23 34 45 56 6A 78 7N 8N 4Q "
+                ".2 23 34 45 56 6A 78 8N 4Q "
                 "AB BC CN  AD DE EF FN  DG GH HI IN  GJ JK KL LN  JN "
                 "NQ N4 N. NO "
                 "OP PQ Q.",
-            arcz_missing="78 8N 7N JN",
+            arcz_missing="78 8N JN",
             arcz_unpredicted="",
         )