patchtest: Add tests from patchtest oe repo

Copy the core components of the patchtest-oe repo into
meta/lib/patchtest in oe-core.

(From OE-Core rev: 257f64f4e4414b78981104aec132b067beb5a92a)

Signed-off-by: Trevor Gamblin <tgamblin@baylibre.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/lib/patchtest/tests/test_metadata_max_length.py

@@ -0,0 +1,26 @@
+# Checks related to patch line lengths
+#
+# Copyright (C) 2016 Intel Corporation
+#
+# SPDX-License-Identifier: GPL-2.0
+
+import base
+import re
+
+class MaxLength(base.Base):
+    add_mark = re.compile('\+ ')
+    max_length = 200
+
+    def test_max_line_length(self):
+        for patch in self.patchset:
+            # for the moment, we are just interested in metadata
+            if patch.path.endswith('.patch'):
+                continue
+            payload = str(patch)
+            for line in payload.splitlines():
+                if self.add_mark.match(line):
+                    current_line_length = len(line[1:])
+                    if current_line_length > self.max_length:
+                        self.fail('Patch line too long (current length %s)' % current_line_length,
+                                  'Shorten the corresponding patch line (max length supported %s)' % self.max_length,
+                                  data=[('Patch', patch.path), ('Line', '%s ...' % line[0:80])])