guard shrink-factor division against floating-point near-zero (#57175) - #57175
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…57175) Summary: fixes react/yoga#1665. **problem:** when all flex children are frozen to their min-width in the first pass, `totalFlexShrinkScaledFactors` is reduced to near-zero by floating-point cancellation rather than exactly 0. the guard in `distributeFreeSpaceSecondPass` uses exact equality (`== 0`), so it never fires, and the second pass divides `remainingFreeSpace` by a value on the order of 1e-7, producing a childSize on the order of 1e11 that overwhelms the min/max clamp. **fix:** replace the exact-zero check with a relative epsilon guard (`shrinkFactorMagnitude < 1e-6f`). when the magnitude is that small, all items were already frozen in the first pass; the safe fallback (`childFlexBasis + flexShrinkScaledFactor`) applies and the subsequent `boundAxisWithAutoMin` clamps correctly to minWidth. regression: `YGFlexShrinkBorderBug.flex_basis_0_border_minwidth_row` reproduces the original crash — 4 children, `borderWidth` difference of 1e-6 across them, all now compute to their correct minWidth. ## Changelog: [Internal] - X-link: react/yoga#1974 Reviewed By: javache Differential Revision: D108030908 Pulled By: cipolleschi
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…57175) Summary: fixes react/yoga#1665. **problem:** when all flex children are frozen to their min-width in the first pass, `totalFlexShrinkScaledFactors` is reduced to near-zero by floating-point cancellation rather than exactly 0. the guard in `distributeFreeSpaceSecondPass` uses exact equality (`== 0`), so it never fires, and the second pass divides `remainingFreeSpace` by a value on the order of 1e-7, producing a childSize on the order of 1e11 that overwhelms the min/max clamp. **fix:** replace the exact-zero check with a relative epsilon guard (`shrinkFactorMagnitude < 1e-6f`). when the magnitude is that small, all items were already frozen in the first pass; the safe fallback (`childFlexBasis + flexShrinkScaledFactor`) applies and the subsequent `boundAxisWithAutoMin` clamps correctly to minWidth. regression: `YGFlexShrinkBorderBug.flex_basis_0_border_minwidth_row` reproduces the original crash — 4 children, `borderWidth` difference of 1e-6 across them, all now compute to their correct minWidth. ## Changelog: [Internal] - X-link: react/yoga#1974 Reviewed By: javache Differential Revision: D108030908 Pulled By: cipolleschi
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Summary: X-link: react/react-native#57175 fixes #1665. **problem:** when all flex children are frozen to their min-width in the first pass, `totalFlexShrinkScaledFactors` is reduced to near-zero by floating-point cancellation rather than exactly 0. the guard in `distributeFreeSpaceSecondPass` uses exact equality (`== 0`), so it never fires, and the second pass divides `remainingFreeSpace` by a value on the order of 1e-7, producing a childSize on the order of 1e11 that overwhelms the min/max clamp. **fix:** replace the exact-zero check with a relative epsilon guard (`shrinkFactorMagnitude < 1e-6f`). when the magnitude is that small, all items were already frozen in the first pass; the safe fallback (`childFlexBasis + flexShrinkScaledFactor`) applies and the subsequent `boundAxisWithAutoMin` clamps correctly to minWidth. regression: `YGFlexShrinkBorderBug.flex_basis_0_border_minwidth_row` reproduces the original crash — 4 children, `borderWidth` difference of 1e-6 across them, all now compute to their correct minWidth. ## Changelog: [Internal] - X-link: #1974 Reviewed By: javache Differential Revision: D108030908 Pulled By: cipolleschi fbshipit-source-id: 3e8d4ef6773bc31703a54005bf610b2432f22d2d
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Summary:
fixes react/yoga#1665.
problem: when all flex children are frozen to their min-width in the first
pass,
totalFlexShrinkScaledFactorsis reduced to near-zero by floating-pointcancellation rather than exactly 0. the guard in
distributeFreeSpaceSecondPassuses exact equality (
== 0), so it never fires, and the second pass dividesremainingFreeSpaceby a value on the order of 1e-7, producing a childSize onthe order of 1e11 that overwhelms the min/max clamp.
fix: replace the exact-zero check with a relative epsilon guard
(
shrinkFactorMagnitude < 1e-6f). when the magnitude is that small, all itemswere already frozen in the first pass; the safe fallback (
childFlexBasis + flexShrinkScaledFactor) applies and the subsequentboundAxisWithAutoMinclampscorrectly to minWidth.
regression:
YGFlexShrinkBorderBug.flex_basis_0_border_minwidth_rowreproducesthe original crash — 4 children,
borderWidthdifference of 1e-6 across them,all now compute to their correct minWidth.
Changelog:
[Internal] -
X-link: react/yoga#1974
Reviewed By: javache
Differential Revision: D108030908
Pulled By: cipolleschi