contrib/gcc-changelog: Check that PR in subject is in changelog

This patch checks that a '[PRnnnn]' and '(PRnnnn)' also appears as PR in the
changelog part of the commit message.  And it does likewise for 'PR comp/nnnn'
except that then also the component name is checked.  (Note that the reverse
is permitted, i.e. PR(s) only appearing in the changelog.)
To avoid false positives, PR numbers in the subject line are ignored,
if 'revert' appears.
Additionally, reject commits with a nonempty second line.

contrib/ChangeLog:

	* gcc-changelog/git_commit.py (pr_regex): Add ?P<pr> for group('pr').
	(subject_pr_regex, subject_pr2_regex): New.
	(GitInfo.__init__, GitCommit.parse_changelog): Check subject PRs.
	* gcc-changelog/git_email.py (SUBJECT_PREFIX, subject_patch_regex): New.
	(GitEmail.__init__): Parse 'Subject:' and pass it to GitInfo.
	* gcc-changelog/test_email.py (test_pr_only_in_subject,
	test_wrong_pr_comp_in_subject, test_copyright_years): New.
	* gcc-changelog/test_patches.txt (0030-PR-c-92746, pr-check1.patch):
	Update to avoid triggering the new check.
	(0001-rs6000-Support-doubleword, pr-wrong-comp.patch,
	copyright-years.patch): New.

1 files changed, 20 insertions, 2 deletions

diff --git a/contrib/gcc-changelog/git_email.py b/contrib/gcc-changelog/git_email.py
index fa62e3a..87b419c 100755
--- a/contrib/gcc-changelog/git_email.py
+++ b/contrib/gcc-changelog/git_email.py
@@ -17,6 +17,7 @@
 # <http://www.gnu.org/licenses/>.  */
 
 import os
+import re
 import sys
 from itertools import takewhile
 
@@ -28,6 +29,8 @@ from unidiff import PatchSet, PatchedFile
 
 DATE_PREFIX = 'Date: '
 FROM_PREFIX = 'From: '
+SUBJECT_PREFIX = 'Subject: '
+subject_patch_regex = re.compile(r'^\[PATCH( \d+/\d+)?\] ')
 unidiff_supports_renaming = hasattr(PatchedFile(), 'is_rename')
 
 
@@ -37,7 +40,9 @@ class GitEmail(GitCommit):
         diff = PatchSet.from_filename(filename)
         date = None
         author = None
+        subject = ''
 
+        subject_last = False
         with open(self.filename, 'r') as f:
             lines = f.read().splitlines()
         lines = list(takewhile(lambda line: line != '---', lines))
@@ -46,8 +51,21 @@ class GitEmail(GitCommit):
                 date = parse(line[len(DATE_PREFIX):])
             elif line.startswith(FROM_PREFIX):
                 author = GitCommit.format_git_author(line[len(FROM_PREFIX):])
+            elif line.startswith(SUBJECT_PREFIX):
+                subject = line[len(SUBJECT_PREFIX):]
+                subject_last = True
+            elif subject_last and line.startswith(' '):
+                subject += line
+            elif line == '':
+                break
+            else:
+                subject_last = False
+
+        if subject:
+            subject = subject_patch_regex.sub('', subject)
         header = list(takewhile(lambda line: line != '', lines))
-        body = lines[len(header) + 1:]
+        # Note: commit message consists of email subject, empty line, email body
+        message = [subject] + lines[len(header):]
 
         modified_files = []
         for f in diff:
@@ -67,7 +85,7 @@ class GitEmail(GitCommit):
             else:
                 t = 'M'
             modified_files.append((target if t != 'D' else source, t))
-        git_info = GitInfo(None, date, author, body, modified_files)
+        git_info = GitInfo(None, date, author, message, modified_files)
         super().__init__(git_info,
                          commit_to_info_hook=lambda x: None)