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Grzegorz MartensandClaude Opus 5.5
4303d49eea
`IndirectObject<f32>` read an object holding `6 0 R` as the number 6, so `/Decode [11 0 R 0]`, with 11 naming 6 and 6 holding 1, read as 6, and `/W` gave glyphs such widths. As anything but a number, such an object was lost. `XRef::get_with` is how every reference is read, to an object stored on its own or in an object stream, so it now follows such objects in a loop, up to 32 references as `Document::resolve` does in #5548. A loop takes no stack however long the chain, and a cycle runs out of references and reads as a missing object, as a reference to nothing does: the image with such a `/Decode` isn't drawn, as with `/Decode [99 0 R 0]`. An object stream isn't reached that way: it has to be a stream stored as that object, and following a reference to one stored inside another let a 1 KB file run out of stack. `XRef::objects` leaves such objects out, or a page came out once more for each one holding a reference to it, and a comment inside a reference counts as white space, as it does everywhere else. Reading an object stream's index now counts against the 64 nested loads, and reads its dictionary alone. That is older than this branch, which only made it slightly worse: a chain of object streams, each with a member of the next for its `/N`, `/First` or `/Length`, recursed with no limit, holding a copy of the chain at each, and aborted on 750 KB with an 8 MiB stack, or 250 KB with 2 MiB, in a test build. Parsing the stream read `/Length` as well as `/N`, two ways to the next stream's index, and a failed index isn't remembered, so the work doubled at each stream: 20 streams in a ring took 20 s on `main`. ISO 32000-2 7.5.7 keeps an object stream's `/Length` out of object streams, so no legal file has a `/Length` chain. Nothing forbids `/N` or `/First` by reference, though no writer I know of makes such a chain. Past the limit it reads as missing unless a stream within 64 of it has been read. `/W` and `/W2` with their list by reference are tested too. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01AmsdeUCdTaD72jkDw2pJKY