checkpatch: Don't enforce char limit on tests.

Although tests ideally also stick to shorter line lengths, it is very
common for fixed text blocks like flows or large packets to be specified
within tests. Checkpatch shouldn't complain about cases like these.

Signed-off-by: Joe Stringer <joe@ovn.org>
Acked-by: Russell Bryant <russell@ovn.org>
Tested-by: Aaron Conole <aconole@redhat.com>

utilities/checkpatch.py

@@ -56,6 +56,13 @@ skip_trailing_whitespace_check = False
 skip_block_whitespace_check = False
 skip_signoff_check = False
 
+# Don't enforce character limit on files that include these characters in their
+# name, as they may have legitimate reasons to have longer lines.
+#
+# Python isn't checked as flake8 performs these checks during build.
+line_length_blacklist = ['.am', '.at', 'etc', '.in', '.m4', '.mk', '.patch',
+                         '.py']
+
 
 def is_added_line(line):
     """Returns TRUE if the line in question is an added line.
@@ -99,14 +106,23 @@ def ovs_checkpatch_parse(text):
     co_authors = []
     parse = 0
     current_file = ''
+    previous_file = ''
     scissors = re.compile(r'^[\w]*---[\w]*')
     hunks = re.compile('^(---|\+\+\+) (\S+)')
     is_signature = re.compile(r'((\s*Signed-off-by: )(.*))$',
                               re.I | re.M | re.S)
     is_co_author = re.compile(r'(\s*(Co-authored-by: )(.*))$',
                               re.I | re.M | re.S)
+    skip_line_length_check = False
 
     for line in text.split('\n'):
+        if current_file != previous_file:
+            previous_file = current_file
+            if any([fmt in current_file for fmt in line_length_blacklist]):
+                skip_line_length_check = True
+            else:
+                skip_line_length_check = False
+
         lineno = lineno + 1
         if len(line) <= 0:
             continue
@@ -154,7 +170,7 @@ def ovs_checkpatch_parse(text):
             if trailing_whitespace_or_crlf(line[1:]):
                 print_line = True
                 print_warning("Line has trailing whitespace", lineno)
-            if len(line[1:]) > 79:
+            if len(line[1:]) > 79 and not skip_line_length_check:
                 print_line = True
                 print_warning("Line is greater than 79-characters long",
                               lineno)