CorruptIndexException

An index sidecar or the index registry cannot be read as this implementation wrote it.

Separate from CorruptBitmapException although a sidecar is mostly bitmaps, because the two are repaired differently and the message has to say which. A damaged posting list is rebuilt by rescanning one segment; a damaged registry has lost an index definition, which no rescan can recover because nobody wrote it down anywhere else.

The failure also covers a sidecar that decodes perfectly but describes something it cannot be describing — a segment number that disagrees with its own filename, an index id that disagrees with the registry, a maximum sequence that disagrees with the base sidecar. A file copied or renamed into place must not be folded in as if it belonged there.