Revert "Relax git_footers parsing to match that of Gerrit (JGit)."

This reverts commit 28a5d5defd13c382af94cd8368b16641752fee88.

Reason for revert: breaks assumption in function for adding footers

Original change's description:
> Relax git_footers parsing to match that of Gerrit (JGit).
> 
> R=​agable@chromium.org
> 
> Bug: 717504
> Change-Id: Ieb6415d55e85b91f11f9052b0fd08cf982b64d51
> Reviewed-on: https://chromium-review.googlesource.com/501849
> Commit-Queue: Andrii Shyshkalov <tandrii@chromium.org>
> Reviewed-by: Aaron Gable <agable@chromium.org>
> 

TBR=agable@chromium.org,machenbach@chromium.org,tandrii@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
Bug: 717504

Change-Id: I9b4d619b2972be8434aff9464f1959fbcb3abd32
Reviewed-on: https://chromium-review.googlesource.com/503030
Reviewed-by: Andrii Shyshkalov <tandrii@chromium.org>
Commit-Queue: Andrii Shyshkalov <tandrii@chromium.org>

git_footers.py

@@ -48,8 +48,6 @@ def split_footers(message):
   Guarantees that:
     (non_footer_lines + footer_lines) == message.splitlines().
     parsed_footers is parse_footer applied on each line of footer_lines.
-      There could be fewer parsed_footers than footer lines if some lines in
-      last paragraph are malformed.
   """
   message_lines = list(message.splitlines())
   footer_lines = []
@@ -63,8 +61,8 @@ def split_footers(message):
     footer_lines = []
 
   footer_lines.reverse()
-  footers = filter(None, map(parse_footer, footer_lines))
-  if not footers:
+  footers = map(parse_footer, footer_lines)
+  if not footer_lines or not all(footers):
     return message_lines, [], []
   return message_lines[:-len(footer_lines)], footer_lines, footers
 

recipes/recipe_modules/bot_update/resources/bot_update.py

@@ -411,9 +411,9 @@ def get_commit_message_footer_map(message):
   for line in lines:
     m = COMMIT_FOOTER_ENTRY_RE.match(line)
     if not m:
-      # If any single line isn't valid, continue anyway for compatibility with
-      # Gerrit (which itself uses JGit for this).
-      continue
+      # If any single line isn't valid, the entire footer is invalid.
+      footers.clear()
+      return footers
     footers[m.group(1)] = m.group(2).strip()
   return footers
 

tests/git_footers_test.py

@@ -59,33 +59,6 @@ My commit message is my best friend. It is my life. I must master it.
         { 'Bug': [''],
           'Cr-Commit-Position': [ self._position ] })
 
-  def testSkippingBadFooterLines(self):
-    message = ('Title.\n'
-               '\n'
-               'Last: paragraph starts\n'
-               'It-may: contain\n'
-               'bad lines, which should be skipped\n'
-               'For: example\n'
-               '(cherry picked from)\n'
-               'And-only-valid: footers taken')
-    self.assertEqual(git_footers.split_footers(message),
-                     (['Title.',
-                       ''],
-                      ['Last: paragraph starts',
-                       'It-may: contain',
-                       'bad lines, which should be skipped',
-                       'For: example',
-                       '(cherry picked from)',
-                       'And-only-valid: footers taken'],
-                      [('Last', 'paragraph starts'),
-                       ('It-may', 'contain'),
-                       ('For', 'example'),
-                       ('And-only-valid', 'footers taken')]))
-    self.assertEqual(git_footers.parse_footers(message),
-                     {'Last': ['paragraph starts'],
-                      'It-May': ['contain'],
-                      'For': ['example'],
-                      'And-Only-Valid': ['footers taken']})
 
   def testGetFooterChangeId(self):
     msg = '\n'.join(['whatever',