Merge pull request #574 from pre-commit/error_whitespace_errors

Fix patch applying when apply.whitespace=error

pre_commit/staged_files_only.py

@@ -45,7 +45,10 @@ def staged_files_only(cmd_runner):
         finally:
             # Try to apply the patch we saved
             try:
-                cmd_runner.run(('git', 'apply', patch_filename), encoding=None)
+                cmd_runner.run(
+                    ('git', 'apply', '--whitespace=nowarn', patch_filename),
+                    encoding=None,
+                )
             except CalledProcessError:
                 logger.warning(
                     'Stashed changes conflicted with hook auto-fixes... '
@@ -55,7 +58,10 @@ def staged_files_only(cmd_runner):
                 # by hooks.
                 # Roll back the changes made by hooks.
                 cmd_runner.run(['git', 'checkout', '--', '.'])
-                cmd_runner.run(('git', 'apply', patch_filename), encoding=None)
+                cmd_runner.run(
+                    ('git', 'apply', patch_filename, '--whitespace=nowarn'),
+                    encoding=None,
+                )
             logger.info('Restored changes from {}.'.format(patch_filename))
     else:
         # There weren't any staged files so we don't need to do anything

tests/staged_files_only_test.py

@@ -340,7 +340,7 @@ bool_product = tuple(itertools.product((True, False), repeat=2))
 def test_crlf(in_git_dir, cmd_runner, crlf_before, crlf_after, autocrlf):
     cmd_output('git', 'config', '--local', 'core.autocrlf', autocrlf)
 
-    before, after = b'1\n2\n', b'3\n4\n'
+    before, after = b'1\n2\n', b'3\n4\n\n'
     before = before.replace(b'\n', b'\r\n') if crlf_before else before
     after = after.replace(b'\n', b'\r\n') if crlf_after else after
 
@@ -349,3 +349,8 @@ def test_crlf(in_git_dir, cmd_runner, crlf_before, crlf_after, autocrlf):
     _write(after)
     with staged_files_only(cmd_runner):
         assert_no_diff()
+
+
+def test_whitespace_errors(in_git_dir, cmd_runner):
+    cmd_output('git', 'config', '--local', 'apply.whitespace', 'error')
+    test_crlf(in_git_dir, cmd_runner, True, True, 'true')