Bug 708373

Summary:	layer/clip nesting too deep
Product:	MuPDF	Reporter:	Jorj <jorj.x.mckie>
Component:	mupdf	Assignee:	MuPDF bugs <mupdf-bugs>
Status:	RESOLVED FIXED
Severity:	normal	CC:	robin.watts
Priority:	P2
Version:	unspecified
Hardware:	All
OS:	All
Customer:		Word Size:	---

Description Jorj 2025-03-25 13:26:11 UTC

PyMuPDF issue: https://github.com/pymupdf/PyMuPDF/issues/4403
Problem file: https://github.com/user-attachments/files/19448199/subset.pdf

Almost all viewers exhibit an extended response time.
This is the output of mutool draw:

$ mutool draw -o test.txt subset.pdf
warning: dropping unclosed PDF processor
limit error: layer/clip nesting too deep
cannot draw 'subset.pdf'

Anything that can be / should be done here?

Comment 1 Robin Watts 2025-03-26 14:47:47 UTC

Fixed with:

commit 0d48b70f9970c77d133d31a070f437cea70f067bAuthor: Robin Watts <Robin.Watts@artifex.com>
Date:   Wed Mar 26 13:08:16 2025 +0000

    Bug 708373: Record clip/layer nesting more efficiently.

    The file in question uses multiple (1000+!) nested clip regions.
    This was running us off the fixed size array. We now store a
    count of clips at each level rather than 1 per level to avoid
    this.

It is an obscenely structured file, with 1000s of nested (non rectangular) clips.

Comment 2 Jorj 2025-03-27 10:47:45 UTC

Confirming that this fix resolves the issue! See PyMuPDF post https://github.com/pymupdf/PyMuPDF/issues/4403#issuecomment-2757572934