D3D: Use an alignment of 1 when uploading zero data to initialize textures.

src/libANGLE/renderer/d3d/TextureD3D.cpp

@@ -713,19 +713,20 @@ gl::Error TextureD3D::initializeContents(const gl::Context *context,
                      imageBytes);
     imageBytes *= image->getHeight() * image->getDepth();
 
-    gl::PixelUnpackState defaultUnpackState;
+    gl::PixelUnpackState zeroDataUnpackState;
+    zeroDataUnpackState.alignment = 1;
 
     angle::MemoryBuffer *zeroBuffer = nullptr;
     ANGLE_TRY(context->getZeroFilledBuffer(imageBytes, &zeroBuffer));
     if (shouldUseSetData(image))
     {
         ANGLE_TRY(mTexStorage->setData(context, imageIndex, image, nullptr, formatInfo.type,
-                                       defaultUnpackState, zeroBuffer->data()));
+                                       zeroDataUnpackState, zeroBuffer->data()));
     }
     else
     {
         gl::Box fullImageArea(0, 0, 0, image->getWidth(), image->getHeight(), image->getDepth());
-        ANGLE_TRY(image->loadData(context, fullImageArea, defaultUnpackState, formatInfo.type,
+        ANGLE_TRY(image->loadData(context, fullImageArea, zeroDataUnpackState, formatInfo.type,
                                   zeroBuffer->data(), false));
 
         // Force an update to the tex storage so we avoid problems with subImage and dirty regions.

src/tests/gl_tests/RobustResourceInitTest.cpp

@@ -803,10 +803,15 @@ TEST_P(RobustResourceInitTestES3, ReadingOutOfboundsCopiedTextureWithUnpackBuffe
     glBufferData(GL_PIXEL_UNPACK_BUFFER, sizeof(bunchOfGreen), bunchOfGreen.data(), GL_STATIC_DRAW);
     EXPECT_GL_NO_ERROR();
 
+    // Use non-multiple-of-4 dimensions to make sure unpack alignment is set in the backends
+    // (http://crbug.com/836131)
+    constexpr int kTextureWidth  = 127;
+    constexpr int kTextureHeight = 127;
+
     // Use GL_ALPHA to force a CPU readback in the D3D11 backend
     GLTexture texAlpha;
     glBindTexture(GL_TEXTURE_2D, texAlpha);
-    glCopyTexImage2D(GL_TEXTURE_2D, 0, GL_ALPHA, x, y, kWidth, kHeight, 0);
+    glCopyTexImage2D(GL_TEXTURE_2D, 0, GL_ALPHA, x, y, kTextureWidth, kTextureHeight, 0);
     EXPECT_GL_NO_ERROR();
 
     // GL_ALPHA cannot be glReadPixels, so copy into a GL_RGBA texture