Early-out of *TexSubImage* calls when the width, height or depth is zero.

src/libGLESv2/libGLESv2.cpp

@@ -5178,6 +5178,12 @@ void __stdcall glTexSubImage2D(GLenum target, GLint level, GLint xoffset, GLint
                 return;
             }
 
+            // Zero sized uploads are valid but no-ops
+            if (width == 0 || height == 0)
+            {
+                return;
+            }
+
             switch (target)
             {
               case GL_TEXTURE_2D:
@@ -6224,6 +6230,12 @@ void __stdcall glTexSubImage3D(GLenum target, GLint level, GLint xoffset, GLint
                 return;
             }
 
+            // Zero sized uploads are valid but no-ops
+            if (width == 0 || height == 0 || depth == 0)
+            {
+                return;
+            }
+
             switch(target)
             {
               case GL_TEXTURE_3D:
@@ -6274,6 +6286,12 @@ void __stdcall glCopyTexSubImage3D(GLenum target, GLint level, GLint xoffset, GL
                 return;
             }
 
+            // Zero sized copies are valid but no-ops
+            if (width == 0 || height == 0)
+            {
+                return;
+            }
+
             gl::Framebuffer *framebuffer = context->getReadFramebuffer();
             gl::Texture *texture = NULL;
             switch (target)
@@ -6391,6 +6409,12 @@ void __stdcall glCompressedTexSubImage3D(GLenum target, GLint level, GLint xoffs
                 return;
             }
 
+            // Zero sized uploads are valid but no-ops
+            if (width == 0 || height == 0)
+            {
+                return;
+            }
+
             switch(target)
             {
               case GL_TEXTURE_3D:

src/libGLESv2/renderer/d3d9/Image9.cpp

@@ -328,6 +328,8 @@ bool Image9::copyToStorage(TextureStorageInterface2DArray *storage, int level, G
 
 bool Image9::copyToSurface(IDirect3DSurface9 *destSurface, GLint xoffset, GLint yoffset, GLsizei width, GLsizei height)
 {
+    ASSERT(width > 0 && height > 0);
+
     if (!destSurface)
         return false;
 

tests/angle_tests/TextureTest.cpp

@@ -23,16 +23,53 @@ protected:
         EXPECT_GL_NO_ERROR();
 
         ASSERT_GL_NO_ERROR();
+
+        const std::string vertexShaderSource = SHADER_SOURCE
+        (
+            precision highp float;
+            attribute vec4 position;
+            varying vec2 texcoord;
+
+            void main()
+            {
+                gl_Position = position;
+                texcoord = (position.xy * 0.5) + 0.5;
+            }
+        );
+
+        const std::string fragmentShaderSource = SHADER_SOURCE
+        (
+            precision highp float;
+            uniform sampler2D tex;
+            varying vec2 texcoord;
+
+            void main()
+            {
+                gl_FragColor = texture2D(tex, texcoord);
+            }
+        );
+
+        mProgram = compileProgram(vertexShaderSource, fragmentShaderSource);
+        if (mProgram == 0)
+        {
+            FAIL() << "shader compilation failed.";
+        }
+
+        mTextureUniformLocation = glGetUniformLocation(mProgram, "tex");
     }
 
     virtual void TearDown()
     {
         glDeleteTextures(1, &mTexture);
+        glDeleteProgram(mProgram);
 
         ANGLETest::TearDown();
     }
 
     GLuint mTexture;
+
+    GLuint mProgram;
+    GLint mTextureUniformLocation;
 };
 
 TEST_F(TextureTest, negative_api_subimage)
@@ -44,3 +81,25 @@ TEST_F(TextureTest, negative_api_subimage)
     glTexSubImage2D(GL_TEXTURE_2D, 0, 1, 1, 1, 1, GL_RGBA, GL_UNSIGNED_BYTE, pixels);
     EXPECT_GL_ERROR(GL_INVALID_VALUE);
 }
+
+TEST_F(TextureTest, zero_sized_uploads)
+{
+    glBindTexture(GL_TEXTURE_2D, mTexture);
+    EXPECT_GL_ERROR(GL_NO_ERROR);
+
+    // Use the texture first to make sure it's in video memory
+    glUseProgram(mProgram);
+    glUniform1i(mTextureUniformLocation, 0);
+    drawQuad(mProgram, "position", 0.5f);
+
+    const GLubyte *pixel[4] = { 0 };
+
+    glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, 0, 0, GL_RGBA, GL_UNSIGNED_BYTE, pixel);
+    EXPECT_GL_NO_ERROR();
+
+    glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, 0, 1, GL_RGBA, GL_UNSIGNED_BYTE, pixel);
+    EXPECT_GL_NO_ERROR();
+
+    glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, 1, 0, GL_RGBA, GL_UNSIGNED_BYTE, pixel);
+    EXPECT_GL_NO_ERROR();
+}