When emulating the Python interpreter, don't print SystemExits tracebacks.

2 files changed, 25 insertions, 1 deletions

diff --git a/coverage/cmdline.py b/coverage/cmdline.py
index 0ab7475..c938368 100644
--- a/coverage/cmdline.py
+++ b/coverage/cmdline.py
@@ -598,8 +598,13 @@ def main():
     try:
         status = CoverageScript().command_line(sys.argv[1:])
     except ExceptionDuringRun:
+        # An exception was caught while running the product code.  The
+        # sys.exc_info() return tuple is packed into an ExceptionDuringRun
+        # exception.  Note that the Python interpreter doesn't print SystemExit
+        # tracebacks, so it's important that we don't also.
         _, err, _ = sys.exc_info()
-        traceback.print_exception(*err.args)
+        if not isinstance(err.args[1], SystemExit):
+            traceback.print_exception(*err.args)
         status = ERR
     except CoverageException:
         _, err, _ = sys.exc_info()
diff --git a/test/test_process.py b/test/test_process.py
index 8e621ad..53dce06 100644
--- a/test/test_process.py
+++ b/test/test_process.py
@@ -170,3 +170,22 @@ class ProcessTest(CoverageTest):
         self.assertTrue('File "throw.py", line 5, in f2' in out)
         self.assertTrue('raise Exception("hey!")' in out)
         self.assertFalse('coverage' in out)
+
+    def test_code_exits(self):
+        self.make_file("exit.py", """\
+            import sys    
+            def f1():
+                print("about to exit..")
+                sys.exit(17)
+
+            def f2():
+                f1()
+
+            f2()
+            """)
+
+        # The important thing is for "coverage run" and "python" to report the
+        # same traceback.
+        out = self.run_command("coverage run exit.py")
+        out2 = self.run_command("python exit.py")
+        self.assertMultiLineEqual(out, out2)