Don't instantiate shaders with non-invertible local matrix

Change-Id: If11f7d57cbf45929632d858f91c02d8f5fa9f442
Reviewed-on: https://skia-review.googlesource.com/7885
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Florin Malita <fmalita@chromium.org>

2 files changed, 18 insertions, 0 deletions

diff --git a/src/core/SkShader.cpp b/src/core/SkShader.cpp
index 9e562c9276..9f97a7a74a 100644
--- a/src/core/SkShader.cpp
+++ b/src/core/SkShader.cpp
@@ -241,11 +241,17 @@ sk_sp<SkShader> SkShader::MakeColorShader(SkColor color) { return sk_make_sp<SkC
 
 sk_sp<SkShader> SkShader::MakeBitmapShader(const SkBitmap& src, TileMode tmx, TileMode tmy,
                                            const SkMatrix* localMatrix) {
+    if (localMatrix && !localMatrix->invert(nullptr)) {
+        return nullptr;
+    }
     return SkMakeBitmapShader(src, tmx, tmy, localMatrix, kIfMutable_SkCopyPixelsMode, nullptr);
 }
 
 sk_sp<SkShader> SkShader::MakePictureShader(sk_sp<SkPicture> src, TileMode tmx, TileMode tmy,
                                             const SkMatrix* localMatrix, const SkRect* tile) {
+    if (localMatrix && !localMatrix->invert(nullptr)) {
+        return nullptr;
+    }
     return SkPictureShader::Make(std::move(src), tmx, tmy, localMatrix, tile);
 }
 
diff --git a/src/effects/gradients/SkGradientShader.cpp b/src/effects/gradients/SkGradientShader.cpp
index 7b91a60f75..03a2db0995 100644
--- a/src/effects/gradients/SkGradientShader.cpp
+++ b/src/effects/gradients/SkGradientShader.cpp
@@ -944,6 +944,9 @@ sk_sp<SkShader> SkGradientShader::MakeLinear(const SkPoint pts[2],
     if (1 == colorCount) {
         return SkShader::MakeColorShader(colors[0], std::move(colorSpace));
     }
+    if (localMatrix && !localMatrix->invert(nullptr)) {
+        return nullptr;
+    }
 
     ColorStopOptimizer opt(colors, pos, colorCount, mode);
 
@@ -980,6 +983,9 @@ sk_sp<SkShader> SkGradientShader::MakeRadial(const SkPoint& center, SkScalar rad
     if (1 == colorCount) {
         return SkShader::MakeColorShader(colors[0], std::move(colorSpace));
     }
+    if (localMatrix && !localMatrix->invert(nullptr)) {
+        return nullptr;
+    }
 
     ColorStopOptimizer opt(colors, pos, colorCount, mode);
 
@@ -1026,6 +1032,9 @@ sk_sp<SkShader> SkGradientShader::MakeTwoPointConical(const SkPoint& start,
             return SkShader::MakeEmptyShader();
         }
     }
+    if (localMatrix && !localMatrix->invert(nullptr)) {
+        return nullptr;
+    }
     EXPAND_1_COLOR(colorCount);
 
     ColorStopOptimizer opt(colors, pos, colorCount, mode);
@@ -1086,6 +1095,9 @@ sk_sp<SkShader> SkGradientShader::MakeSweep(SkScalar cx, SkScalar cy,
     if (1 == colorCount) {
         return SkShader::MakeColorShader(colors[0], std::move(colorSpace));
     }
+    if (localMatrix && !localMatrix->invert(nullptr)) {
+        return nullptr;
+    }
 
     auto mode = SkShader::kClamp_TileMode;