Revert "Fix div-by-zero loophole in gradient factory func"

This reverts commit c34dd6c526.

Reason for revert: Speculative fix for Chrome roll (gradient layout test failures)

Original change's description:
> Fix div-by-zero loophole in gradient factory func
> 
> Bug: oss-fuzz:10373
> Change-Id: I4277fb63e3186ee34feaf09ecf6aeddeb532f9c1
> Reviewed-on: https://skia-review.googlesource.com/c/168269
> Reviewed-by: Kevin Lubick <kjlubick@google.com>
> Commit-Queue: Michael Ludwig <michaelludwig@google.com>

TBR=jvanverth@google.com,kjlubick@google.com,michaelludwig@google.com

Change-Id: I6333390d2ecc559ad98bd4d734ab1c674e23037f
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: oss-fuzz:10373
Reviewed-on: https://skia-review.googlesource.com/c/168460
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
This commit is contained in:
Brian Osman 2018-11-06 00:41:40 +00:00 committed by Skia Commit-Bot
parent 422f95bce8
commit 2dfab27d69
2 changed files with 11 additions and 17 deletions

View File

@ -694,23 +694,19 @@ sk_sp<SkShader> SkGradientShader::MakeTwoPointConical(const SkPoint& start,
if (startRadius < 0 || endRadius < 0) {
return nullptr;
}
if (SkScalarNearlyZero((start - end).length())) {
// If the center positions are the same, then the gradient is the radial variant of a
// 2 pt conical gradient, or an actual radial gradient (startRadius == 0), or it is
// fully degenerate (startRadius == endRadius).
if (SkScalarNearlyEqual(startRadius, endRadius)) {
// Degenerate case
return SkShader::MakeEmptyShader();
} else if (SkScalarNearlyZero(startRadius)) {
// We can treat this gradient as radial, which is faster.
return MakeRadial(start, endRadius, colors, std::move(colorSpace), pos, colorCount,
mode, flags, localMatrix);
}
if (SkScalarNearlyZero((start - end).length()) && SkScalarNearlyZero(startRadius)) {
// We can treat this gradient as radial, which is faster.
return MakeRadial(start, endRadius, colors, std::move(colorSpace), pos, colorCount,
mode, flags, localMatrix);
}
if (!valid_grad(colors, pos, colorCount, mode)) {
return nullptr;
}
if (startRadius == endRadius) {
if (start == end || startRadius == 0) {
return SkShader::MakeEmptyShader();
}
}
if (localMatrix && !localMatrix->invert(nullptr)) {
return nullptr;
}

View File

@ -55,10 +55,8 @@ sk_sp<SkShader> SkTwoPointConicalGradient::Create(const SkPoint& c0, SkScalar r0
Type gradientType;
if (SkScalarNearlyZero((c0 - c1).length())) {
if (SkScalarNearlyZero(SkTMax(r0, r1)) || SkScalarNearlyEqual(r0, r1)) {
// Degenerate case; avoid dividing by zero. Should have been caught by caller but
// just in case, recheck here.
return nullptr;
if (SkScalarNearlyZero(SkTMax(r0, r1))) {
return nullptr; // Degenerate case; avoid dividing by zero.
}
// Concentric case: we can pretend we're radial (with a tiny twist).
const SkScalar scale = sk_ieee_float_divide(1, SkTMax(r0, r1));