Re: GIT: Monotonically increasing trunk and release branch ids

[Jakub Jelinek <jakub at redhat dot com>]

On Fri, Jan 10, 2020 at 07:50:02PM +0100, Jakub Jelinek wrote:
> The changes I was asking for is, for gcc master and releases/gcc-* branch
> commits to have the monotonically increasing short ids (printed by git descr
> <commithash> with the git aliases I've posted) both somewhere early
> in the subject before the one-line description, and somewhere in the body
> too.  For release branch commits, perhaps the

Here it is in patch form (against Joseph's git-hooks copy), but untested
(both because the repo isn't converted yet, basepoints don't exist there
either and because not sure how exactly it can be tested in a dry-run, say
sending me mail instead of to the public list etc.).
So, all I did test is some simple thing in python3 interactively because
it is close to 20 years since I used python regularly.

diff --git a/hooks/updates/__init__.py b/hooks/updates/__init__.py
index c5d8181..4ddc566 100644
--- a/hooks/updates/__init__.py
+++ b/hooks/updates/__init__.py
@@ -299,11 +299,31 @@ class AbstractUpdate(object):
             # name in full to label the branch name.
             branch = '(%s)' % self.ref_name
 
-        subject = '[%(repo)s%(branch)s] %(subject)s' % {
-            'repo': self.email_info.project_name,
-            'branch': branch,
-            'subject': commit.subject[:SUBJECT_MAX_SUBJECT_CHARS],
-            }
+        # GCC monotonically increasing commit ids.
+        rev_id = ''
+        rev_id_short = ''
+        if self.email_info.project_name == 'gcc'
+           and (self.short_ref_name == 'master'
+                or self.short_ref_name.startswith('releases/gcc-')):
+            rev_id = git.describe(commit.rev, all=True,
+                                  match='basepoints/gcc-[0-9]*')
+            if rev_id.starts_with('tags/basepoints/gcc-'):
+                rev_id = 'r' + rev_id[len('tags/basepoints/gcc-'):]
+                rev_id_short = rev_id[:rev_id.find('-g')]
+            else:
+                rev_id = ''
+
+        if not rev_id:
+            subject = '[%(repo)s%(branch)s] %(subject)s' % {
+                'repo': self.email_info.project_name,
+                'branch': branch,
+                'subject': commit.subject[:SUBJECT_MAX_SUBJECT_CHARS],
+                }
+        else:
+            subject = '%(rev_id)s %(subject)s' % {
+                'rev_id': rev_id_short,
+                'subject': commit.subject[:SUBJECT_MAX_SUBJECT_CHARS],
+                }
 
         # Generate the body of the email in two pieces:
         #   1. The commit description without the patch;
@@ -322,6 +342,10 @@ class AbstractUpdate(object):
         # by stripping it from the output.
 
         body = git.log(commit.rev, max_count="1") + '\n'
+
+        if rev_id:
+            body = re.sub(r'^commit ' + commit.rev', 'commit ' + rev_id,
+                          body, 1, re.M)
         if git_config('hooks.commit-url') is not None:
             url_info = {'rev': commit.rev,
                         'ref_name': self.ref_name}


	Jakub