Update credits_git_gen tool to also parse co-authors in commit messages,

Co-authors listed following the `Co-authored-by:` format in a commit
message will be automatically added to the list of contributors.

Further more, it is now possible to overwrite authors informations from
git commits with embedded data, in case it is necessary to correct some
commit's author information after the commit has been pushed.

Implements #109438.

Pull Request: https://projects.blender.org/blender/blender/pulls/109468

tools/utils/credits_git_gen.py

@@ -11,6 +11,7 @@ Example use:
 
 from git_log import GitCommitIter
 import unicodedata as ud
+import re
 
 # -----------------------------------------------------------------------------
 # Lookup Table to clean up the credits
@@ -91,6 +92,15 @@ author_table = {
     "Yiming Wu": "YimingWu",
 }
 
+# Mapping from a comit hash to additional authors.
+# Fully overwrite authors gathered from git commit info.
+# Intended usage: Correction of info stored in git commit itself.
+# Note that the names of the authors here are assumed fully valid and usable as-is.
+commit_authors_overwrite = {
+    # Format: {full_git_hash: (tuple, of, authors),}.
+    # Example:
+    # b"a60c1e5bb814078411ce105b7cf347afac6f2afd": ("Blender Foundation",  "Suzanne", "Ton"),
+}
 
 # -----------------------------------------------------------------------------
 # Class for generating credits
@@ -111,23 +121,40 @@ class Credits:
         "users",
     )
 
+    # Expected to cover the following formats (the e-mail address is not captured if present):
+    #    `Co-authored-by: Blender Foundation`
+    #    `Co-authored-by: Blender Foundation <foundation@blender.org>`
+    #    `Co-authored-by: Blender Foundation <Suzanne>`
+    GIT_COMMIT_COAUTHORS_RE = re.compile(r"^Co-authored-by:[ \t]*(?P<author>[ \w\t]*\w)(?:$|[ \t]*<)", re.MULTILINE)
+
     def __init__(self):
         self.users = {}
 
-    def process_commit(self, c):
-        # Normalize author string into canonical form, prevents duplicate credit users
-        author = ud.normalize('NFC', c.author)
-        author = author_table.get(author, author)
-        year = c.date.year
-        cu = self.users.get(author)
-        if cu is None:
-            cu = self.users[author] = CreditUser()
-            cu.year_min = year
-            cu.year_max = year
+    @classmethod
+    def commit_authors_get(cls, c):
+        authors = commit_authors_overwrite.get(c.sha1, None)
+        if authors is not None:
+            # Ignore git commit info for these having an entry in commit_authors_overwrite.
+            return [author_table.get(author, author) for author in authors]
 
-        cu.commit_total += 1
-        cu.year_min = min(cu.year_min, year)
-        cu.year_max = max(cu.year_max, year)
+        authors = [c.author] + cls.GIT_COMMIT_COAUTHORS_RE.findall(c.body)
+        # Normalize author string into canonical form, prevents duplicate credit users
+        authors = [ud.normalize('NFC', author) for author in authors]
+        return [author_table.get(author, author) for author in authors]
+
+    def process_commit(self, c):
+        authors = self.commit_authors_get(c)
+        year = c.date.year
+        for author in authors:
+            cu = self.users.get(author)
+            if cu is None:
+                cu = self.users[author] = CreditUser()
+                cu.year_min = year
+                cu.year_max = year
+
+            cu.commit_total += 1
+            cu.year_min = min(cu.year_min, year)
+            cu.year_max = max(cu.year_max, year)
 
     def process(self, commit_iter):
         for i, c in enumerate(commit_iter):