Quilt-style patches that add multiple files in a row fail to parse

[cartr]

When you try to parse the following patch file with e.g. PatchSet.from_string, a UnidiffParseError is thrown:

--- /dev/null
+++ b/1.txt
@@ -0,0 +1 @@
+a
--- /dev/null
+++ b/2.txt
@@ -0,0 +1 @@
+b

Traceback (most recent call last):
  File "<console>", line 1, in <module>
  File "/lib/python3.14/site-packages/unidiff/patch.py", line 639, in from_string
    return cls(cls._convert_string(data, encoding, errors),
               metadata_only=metadata_only)
  File "/lib/python3.14/site-packages/unidiff/patch.py", line 449, in __init__
    self._parse(data, encoding=encoding, metadata_only=metadata_only)
    ~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/lib/python3.14/site-packages/unidiff/patch.py", line 548, in _parse
    raise UnidiffParseError('Target without source: %s' % line)
unidiff.errors.UnidiffParseError: Target without source: +++ b/2.txt

(The quilt utility used in Debian packaging generates unified diff files in this format. Here's a real-world example: https://sources.debian.org/patches/glibc/2.41-12+deb13u3/alpha/submitted-fts64.diff/ )

I suspect the issue here is that, because the source filenames are both /dev/null, this "processing a rename" condition gets incorrectly used when parsing the second --- /dev/null line:

python-unidiff/unidiff/patch.py

Lines 533 to 539 in 5ff054b

	# reset current file, unless we are processing a rename
	# (in that case, source files should match)
	if current_file is not None and not (
	current_file.source_file == source_file):
	current_file = None
	elif current_file is not None:
	current_file.source_timestamp = source_timestamp

The condition should probably be updated to check whether current_file has any hunks, or track the "in the middle of Git-style patch info" state in some other more robust way.

[matiasb]

Thanks for the report, reproduced, and your notes look correct. Preparing a fix.