Reject git refs that begin with a dash#116
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extractProtos passed the ref straight into 'git archive --format=tar <ref> -- ...', in git's option position. A ref such as --output=/path, --remote=url or --exec=cmd was therefore interpreted as a git-archive option rather than a tree-ish, letting a caller redirect the archive to an arbitrary file or reach a remote. A legitimate git ref never starts with '-', so reject those before invoking git.
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Problem
Git.extractProtospassed the caller-suppliedrefstraight into git's option position:Because
refsits before--, a ref that looks like a flag is parsed bygit archiveas an option, not a tree-ish:--output=/path/x.tarwrites the archive to an arbitrary file (silently overwriting it); tar then reads empty stdin and the diff proceeds against an empty tree;--remote=<url>/--exec=<cmd>make git contact a remote.Any automation that builds the ref from external input inherits this.
Fix
A legitimate git ref/tree-ish never begins with
-, so reject such refs up front with a clear error before invoking git. (git archive's own--end-of-optionsmarker can't be used here — it also neutralizes the--path separator, breaking the pathspec.)Test
A regression test (red before the fix):
extractProtos("--output=<file>")against a real repo now returnsLeftand does not create the target file. The existing extract/missing-ref tests still pass.