test: add one more test for the specific nedbat#996 use

tests/test_parser.py

@@ -822,6 +822,24 @@ def test_multiline_exclusion_no_source(self) -> None:
         assert parser.raw_statements == set()
         assert parser.statements == set()
 
+    def test_multiline_exclusion_all_lines_must_match(self) -> None:
+        # https://github.com/nedbat/coveragepy/issues/996
+        regex = r"except ValueError:\n *print\('false'\)"
+        parser = self.parse_text("""\
+            try:
+                a = 2
+                print('false')
+            except ValueError:
+                print('false')
+            except ValueError:
+                print('something else')
+            except IndexError:
+                print('false')
+            """, regex)
+        assert parser.lines_matching(regex) == {4, 5}
+        assert parser.raw_statements == {1, 2, 3, 4, 5, 6, 7, 8, 9}
+        assert parser.statements == {1, 2, 3, 6, 7, 8, 9}
+
     def test_multiline_exclusion_multiple_matches(self) -> None:
         regex = r"print\('.*'\)\n\s+. = \d"
         parser = self.parse_text("""\