gcc-changelog: workaround for utf8 filenames

contrib/ChangeLog:

	* gcc-changelog/git_commit.py: Add decode_path function.
	* gcc-changelog/git_email.py: Use it in order to solve
	utf8 encoding filename issues.
	* gcc-changelog/git_repository.py: Likewise.
	* gcc-changelog/test_email.py: Test it.

contrib/gcc-changelog/git_commit.py

@@ -174,6 +174,24 @@ REVIEW_PREFIXES = ('reviewed-by: ', 'reviewed-on: ', 'signed-off-by: ',
 DATE_FORMAT = '%Y-%m-%d'
 
 
+def decode_path(path):
+    # When core.quotepath is true (default value), utf8 chars are encoded like:
+    # "b/ko\304\215ka.txt"
+    #
+    # The upstream bug is fixed:
+    # https://github.com/gitpython-developers/GitPython/issues/1099
+    #
+    # but we still need a workaround for older versions of the library.
+    # Please take a look at the explanation of the transformation:
+    # https://stackoverflow.com/questions/990169/how-do-convert-unicode-escape-sequences-to-unicode-characters-in-a-python-string
+
+    if path.startswith('"') and path.endswith('"'):
+        return (path.strip('"').encode('utf8').decode('unicode-escape')
+                .encode('latin-1').decode('utf8'))
+    else:
+        return path
+
+
 class Error:
     def __init__(self, message, line=None):
         self.message = message
@@ -303,14 +321,6 @@ class GitCommit:
                                      'separately from normal commits'))
             return
 
-        # check for an encoded utf-8 filename
-        hint = 'git config --global core.quotepath false'
-        for modified, _ in self.info.modified_files:
-            if modified.startswith('"') or modified.endswith('"'):
-                self.errors.append(Error('Quoted UTF8 filename, please set: '
-                                         f'"{hint}"', modified))
-                return
-
         all_are_ignored = (len(project_files) + len(ignored_files)
                            == len(self.info.modified_files))
         self.parse_lines(all_are_ignored)

contrib/gcc-changelog/git_email.py

@@ -22,7 +22,7 @@ from itertools import takewhile
 
 from dateutil.parser import parse
 
-from git_commit import GitCommit, GitInfo
+from git_commit import GitCommit, GitInfo, decode_path
 
 from unidiff import PatchSet, PatchedFile
 
@@ -52,8 +52,8 @@ class GitEmail(GitCommit):
         modified_files = []
         for f in diff:
             # Strip "a/" and "b/" prefixes
-            source = f.source_file[2:]
-            target = f.target_file[2:]
+            source = decode_path(f.source_file)[2:]
+            target = decode_path(f.target_file)[2:]
 
             if f.is_added_file:
                 t = 'A'

contrib/gcc-changelog/git_repository.py

@@ -26,7 +26,7 @@ except ImportError:
     print('  Debian, Ubuntu: python3-git')
     exit(1)
 
-from git_commit import GitCommit, GitInfo
+from git_commit import GitCommit, GitInfo, decode_path
 
 
 def parse_git_revisions(repo_path, revisions, strict=True):
@@ -51,11 +51,11 @@ def parse_git_revisions(repo_path, revisions, strict=True):
                     # Consider that renamed files are two operations:
                     # the deletion of the original name
                     # and the addition of the new one.
-                    modified_files.append((file.a_path, 'D'))
+                    modified_files.append((decode_path(file.a_path), 'D'))
                     t = 'A'
                 else:
                     t = 'M'
-                modified_files.append((file.b_path, t))
+                modified_files.append((decode_path(file.b_path), t))
 
             date = datetime.utcfromtimestamp(c.committed_date)
             author = '%s  <%s>' % (c.author.name, c.author.email)

contrib/gcc-changelog/test_email.py

@@ -402,4 +402,5 @@ class TestGccChangelog(unittest.TestCase):
 
     def test_bad_unicode_chars_in_filename(self):
         email = self.from_patch_glob('0001-Add-horse2.patch')
-        assert email.errors[0].message.startswith('Quoted UTF8 filename')
+        assert not email.errors
+        assert email.changelog_entries[0].files == ['koníček.txt']