fix(#263): carry OCCT kernel patch — ShapeFix_Face non-face context replacement#265
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… replacement Root-caused the upstream OCCT crash behind #263 (Open-Cascade-SAS/OCCT#1322): ShapeFix_Face::Perform casts `Context()->Apply(myFace)` to TopoDS_Face without a type check. When an earlier fix in the shared ReShape context has replaced the face with a COMPOUND (a self-intersecting face split into several faces), Apply() returns a non-face; the unchecked cast builds an invalid face handle over a compound TShape and corrupts the heap — aborting with an uncatchable OS signal (FixOrientation → BRep_Tool::Curve → BRep_TEdge::EmptyCopy, SIGSEGV/SIGBUS at varying addresses). Found by linking a debug-built ShapeFix_Face.cxx over the prebuilt lib: at -O0 the bad cast throws Standard_TypeMismatch at ShapeFix_Face.cxx:383 with S.type=COMPOUND while myFace.type=FACE. Patch guards the cast (return early when S is not a face — the replacement is already in the context). Validated via single-TU override-link at -O2: the bowtie reproducer and all four crash-repro fixtures survive; ShapeFix output on valid box/sphere/cylinder is byte-identical to stock. Takes effect on the next xcframework rebuild; until then v1.8.3's in-wrapper occtHasSelfIntersectingWire guard prevents the crash from reaching this code. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
ShapeFix_Face::Perform casts Context()->Apply(myFace) to TopoDS_Face in three places (the FixWire block, the per-subface loop, and the NeedCheckSplitWire block), all unguarded. The compound replacement already exists on entry to Perform (recorded by a prior face's fix), so a single guard at the top — return early when Apply(myFace) is not a face — covers all three. Cleaner than the per-site guard and the bowtie prism now heals to a valid 8-face solid (was: returned the compound unchanged). Validated via -O2 override-link; box/sphere ShapeFix output unchanged. Matches the upstream PR. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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Upstream fix submitted: Open-Cascade-SAS/OCCT#1323 (same top-of-Perform guard + a GTest regression case). When that merges and ships in an OCCT release, this carried patch can be dropped. |
Rebuilds the xcframework from occt-src V8_0_0_p1 + the carried ShapeFix_Face guard (Scripts/patches/0001). Bumps the binaryTarget URL to v1.8.4 and the checksum to the new zip. Full suite green against the new binary (the only non-passes are the known flaky cone STEP round-trip and a construction-layer count test — both pass in isolation and are unaffected by the guard, which only triggers on a non-face context replacement). Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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Draft — carries the upstream OCCT kernel fix for #263. Takes effect only on the next xcframework rebuild; the in-wrapper guard shipped in v1.8.3 (#264) protects consumers until then.
Root cause (upstream OCCT — Open-Cascade-SAS/OCCT#1322)
ShapeFix_Face::Perform(ShapeFix_Face.cxx:382-383) does:When an earlier fix sharing the same
ShapeBuild_ReShapecontext has replaced the face with a compound (a self-intersecting face split into several faces),Apply()returns a non-face.TopoDS::Faceover a compoundTShapebuilds an invalid face handle → heap corruption → uncatchable OS signal downstream (FixOrientation→BRep_Tool::Curve→BRep_TEdge::EmptyCopy, SIGSEGV/SIGBUS at varying addresses — the exact #263 backtrace).Pinned by linking a debug-built
ShapeFix_Face.cxxover the prebuilt lib: at-O0the cast throwsStandard_TypeMismatchat line 383 withS.type=COMPOUND,myFace.type=FACE(on the 6th of 6 prism faces; the first 5 fix cleanly).Fix
Guard the cast — if
Sis not aTopAbs_FACE, record it as the result and return (the replacement is already in the context; nothing to fix here). One carried patch:Scripts/patches/0001-ShapeFix_Face-guard-non-face-context-replacement-263.patch.Validation (single-TU override-link at -O2, no full rebuild)
OCCTReconstructcrash-reprofixtures (b1214/b693/b135/b106): survive.ShapeFix_Shapeoutput on valid box/sphere/cylinder is byte-identical to stock (the guard only triggers for a non-face replacement, which never happens for a well-formed face).Next steps
OCCT.xcframeworkwith the patch (Scripts/build-occt.sh), attach the.zipasset, bumpPackage.swiftURL+checksum — then the in-wrapper guard becomes belt-and-suspenders.🤖 Generated with Claude Code