Utensil's Zettelkasten-style forest of evergreen notes on math and tech.
utensil.tngl.sh/forest/
fix(dvisvgm): iter 70 — patch upstream FontEngine.cpp:93 off-by-one to stop substr OOB
Root cause for ag-0018, uts-001F (x2), ca-000J tikz-cd placeholders:
dvisvgm 3.6's setFont() enters the sys:// branch on ANY name with
size <= 6 (because the bool is || not &&), then unconditionally calls
fname.substr(6) which throws basic_string::substr on names shorter
than 6 chars. Iter 67's stashed dvisvgm stderr showed __pos=6 > size=3
on a 3-char fname — exact match for this bug.
Fix: flip <= to > and || to && so only true sys://... paths enter the
branch. Triggers a build-depot rebuild (~14m) because dvisvgm is in
the depot NAR closure.
[AGENT: kael]
+13
+13
flake.nix
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flake.nix
···
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# in this nixpkgs revision).
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texlive.bin.core
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];
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# iter 70 — patch upstream off-by-one in FontEngine.cpp:93. The
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# original condition `fname.size() <= 6 || fname.substr(0,6) == "sys://"`
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# enters the branch on ANY short name (size <= 6), then calls
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# fname.substr(6) which throws basic_string::substr on a sub-6-char
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# string. Flip <= to > and || to && so only legit "sys://..." paths
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# enter; substr(6) is then always safe. Confirmed crash trigger for
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# ag-0018 / uts-001F / ca-000J tikz-cd via iter 67 stashed
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# _debug-failures.log (__pos=6 > size=3 on a 3-char fname).
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postPatch = ''
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substituteInPlace src/FontEngine.cpp \
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--replace 'fname.size() <= 6 || fname.substr(0, 6) == "sys://"' \
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'fname.size() > 6 && fname.substr(0, 6) == "sys://"'
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'';
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# autotools default — configure + make + make install.
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};
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