Use NUL character to extract meta and path from git diff

Use NUL character instead of semicolon to extract meta and path. Avoid errors in during git diff when dealing with filenames containing semicolons

git/diff.py

@@ -509,9 +509,9 @@ def _index_from_patch_format(cls, repo: 'Repo', proc: Union['Popen', 'Git.AutoIn
     def _handle_diff_line(lines_bytes: bytes, repo: 'Repo', index: DiffIndex) -> None:
         lines = lines_bytes.decode(defenc)
 
-        for line in lines.split(':')[1:]:
-            meta, _, path = line.partition('\x00')
-            path = path.rstrip('\x00')
+        it = iter(lines.split('\x00'))
+        for meta, path in zip(it, it):
+            meta = meta[1:]
             a_blob_id: Optional[str]
             b_blob_id: Optional[str]
             old_mode, new_mode, a_blob_id, b_blob_id, _change_type = meta.split(None, 4)