commit cc70083fbf76fd86b901fffdcce40d0f53787fc8
author Stephen White <senorblanco@chromium.org> Wed Feb 15 11:45:16 2017 -0500
committer Skia Commit-Bot <skia-commit-bot@chromium.org> Wed Feb 15 17:42:26 2017 +0000
tree a8ee6fff2dbd19c04ab3d336b21df289bd7530c8
parent 1c8e82b72bfeb1a02297688cf082c365b62705f7

GrTessellator (AA): null GrGeometryProcessor crash fix.

Add a null-check on geometry processor creation.

Add a test which exercises it: AA tessellator, with a non-invertible
matrix and a fragment processor which needs local coords (e.g., linear
gradient).

BUG=691902

Change-Id: I005b893aed58d3ad2500c41501045ac94b0b4b95
Reviewed-on: https://skia-review.googlesource.com/8462
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Stephen White <senorblanco@chromium.org>

src/gpu/ops/GrTessellatingPathRenderer.cpp

diff --git a/src/gpu/ops/GrTessellatingPathRenderer.cpp b/src/gpu/ops/GrTessellatingPathRenderer.cpp
index 6ebffca..3acb091 100644
--- a/src/gpu/ops/GrTessellatingPathRenderer.cpp
+++ b/src/gpu/ops/GrTessellatingPathRenderer.cpp
@@ -297,6 +297,9 @@
                                                    fViewMatrix);
             }
         }
+        if (!gp.get()) {
+            return;
+        }
         if (fAntiAlias) {
             this->drawAA(target, gp.get());
         } else {

tests/TessellatingPathRendererTests.cpp

diff --git a/tests/TessellatingPathRendererTests.cpp b/tests/TessellatingPathRendererTests.cpp
index 90d2ba5..f429df3 100644
--- a/tests/TessellatingPathRendererTests.cpp
+++ b/tests/TessellatingPathRendererTests.cpp
@@ -12,6 +12,7 @@
 #if SK_SUPPORT_GPU
 #include "GrContext.h"
 #include "ops/GrTessellatingPathRenderer.h"
+#include "SkGradientShader.h"
 
 /*
  * These tests pass by not crashing, hanging or asserting in Debug.
@@ -249,12 +250,39 @@
     return path;
 }
 
-static void test_path(GrResourceProvider* rp, GrRenderTargetContext* renderTargetContext,
-                      const SkPath& path) {
+// A simple concave path. Test this with a non-invertible matrix.
+static SkPath create_path_17() {
+    SkPath path;
+    path.moveTo(20, 20);
+    path.lineTo(80, 20);
+    path.lineTo(30, 30);
+    path.lineTo(20, 80);
+    return path;
+}
+
+static sk_sp<GrFragmentProcessor> create_linear_gradient_processor(GrContext* ctx) {
+    SkPoint pts[2] = { {0, 0}, {1, 1} };
+    SkColor colors[2] = { SK_ColorGREEN, SK_ColorBLUE };
+    sk_sp<SkShader> shader = SkGradientShader::MakeLinear(
+        pts, colors, nullptr, SK_ARRAY_COUNT(colors), SkShader::kClamp_TileMode);
+    SkShader::AsFPArgs args(
+        ctx, &SkMatrix::I(), &SkMatrix::I(), SkFilterQuality::kLow_SkFilterQuality, nullptr);
+    return shader->asFragmentProcessor(args);
+}
+
+static void test_path(GrResourceProvider* rp,
+                      GrRenderTargetContext* renderTargetContext,
+                      const SkPath& path,
+                      const SkMatrix& matrix = SkMatrix::I(),
+                      GrAAType aaType = GrAAType::kNone,
+                      sk_sp<GrFragmentProcessor> fp = nullptr) {
     GrTessellatingPathRenderer tess;
 
     GrPaint paint;
     paint.setXPFactory(GrPorterDuffXPFactory::Get(SkBlendMode::kSrc));
+    if (fp) {
+        paint.addColorFragmentProcessor(fp);
+    }
 
     GrNoClip noClip;
     GrStyle style(SkStrokeRec::kFill_InitStyle);
@@ -264,9 +292,9 @@
                                       &GrUserStencilSettings::kUnused,
                                       renderTargetContext,
                                       &noClip,
-                                      &SkMatrix::I(),
+                                      &matrix,
                                       &shape,
-                                      GrAAType::kNone,
+                                      aaType,
                                       false};
     tess.drawPath(args);
 }
@@ -303,5 +331,8 @@
     test_path(rp, rtc.get(), create_path_14());
     test_path(rp, rtc.get(), create_path_15());
     test_path(rp, rtc.get(), create_path_16());
+    SkMatrix nonInvertibleMatrix = SkMatrix::MakeScale(0, 0);
+    sk_sp<GrFragmentProcessor> fp(create_linear_gradient_processor(ctx));
+    test_path(rp, rtc.get(), create_path_17(), nonInvertibleMatrix, GrAAType::kCoverage, fp);
 }
 #endif