Dulwich doesn't sanitize commit subjects in `porcelain.format_patch`

Impactdulwich.porcelain.formatpatchoutdir=... derives each patch filename from the commit's subject line. Prior to this fix, getsummary only replaced spaces with dashes - path separators /, \, parent-directory components .., and other filename-hostile characters e.g. : were preserved verbatim and...

CVE-2026-47712

Dulwich is a pure-Python implementation of the Git file formats and protocols. Starting in version 0.24.0 and prior to version 1.2.5, dulwich.porcelain.formatpatchoutdir=... derives each patch filename from the commit's subject line. Prior to this fix, getsummary only replaced spaces with dashes ...