Merge branch '6.x-maintenance'

3 files changed, 12 insertions, 5 deletions

diff --git a/.gitignore b/.gitignore
index 3ec9ade..d140f6f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -8,3 +8,5 @@ build
 docs/_build
 click.egg-info
 .tox
+.cache
+.ropeproject
diff --git a/CHANGES b/CHANGES
index 6fabe36..596bfb1 100644
--- a/CHANGES
+++ b/CHANGES
@@ -27,6 +27,7 @@ Version 6.8
 
 - Disabled sys._getframes() on Python interpreters that don't support it. See
   #728.
+- Fix bug in test runner when calling ``sys.exit`` with ``None``. See #739.
 
 Version 6.7
 -----------
diff --git a/click/testing.py b/click/testing.py
index 09d37a7..ae36d10 100644
--- a/click/testing.py
+++ b/click/testing.py
@@ -197,6 +197,7 @@ class CliRunner(object):
             return char
 
         default_color = color
+
         def should_strip_ansi(stream=None, color=None):
             if color is None:
                 return not default_color
@@ -285,21 +286,24 @@ class CliRunner(object):
                 cli.main(args=args or (),
                          prog_name=self.get_default_prog_name(cli), **extra)
             except SystemExit as e:
-                if e.code != 0:
-                    exception = e
-
                 exc_info = sys.exc_info()
-
                 exit_code = e.code
+                if exit_code is None:
+                    exit_code = 0
+
+                if exit_code != 0:
+                    exception = e
+
                 if not isinstance(exit_code, int):
                     sys.stdout.write(str(exit_code))
                     sys.stdout.write('\n')
                     exit_code = 1
+
             except Exception as e:
                 if not catch_exceptions:
                     raise
                 exception = e
-                exit_code = -1
+                exit_code = 1
                 exc_info = sys.exc_info()
             finally:
                 sys.stdout.flush()