rastrillo / fiesta Public

Test that a hashed twin with other bytes is never listed

Fingerprinted lists a hashed asset only when its bytes equal its
plain twin's, so a corrupted copy under the right name is never told
to browsers as immutable. No test held that: the test's wrong twin
had a name whose hex was not the plain file's hash, so the name
lookup already left it out, and with the byte comparison deleted
the test still passed.

The new fixture is a twin under the plain file's true hashed name
holding other bytes. It is not listed.

This is a test of code that already does the right thing, so it is
labelled already passing. The mutation that turns it red: in
Fingerprinted, drop the byte comparison and keep only the name
lookup. With that mutation the new test fails, listing the corrupted
twin, and the old test passes.

Minor: the corrupted hashed-twin case has no regression test (internal/gallery/hashed_test.go:24). Add a twin named with the plain file's real hash but holding different bytes, and assert it's excluded. Show it red with the byte-equality check removed.

A twin under the plain file's real hashed name but with other bytes is excluded by Fingerprinted; red with the byte check removed.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>