Added tests for clear issues.

tests/angle_tests/ClearTest.cpp

+#include "ANGLETest.h"
+
+class ClearTest : public ANGLETest
+{
+protected:
+    ClearTest()
+    {
+        setWindowWidth(128);
+        setWindowHeight(128);
+        setRedBits(8);
+        setGreenBits(8);
+        setBlueBits(8);
+        setAlphaBits(8);
+        setDepthBits(24);
+    }
+
+    virtual void SetUp()
+    {
+        ANGLETest::SetUp();
+
+        const std::string vertexShaderSource = SHADER_SOURCE
+        (
+            precision highp float;
+            attribute vec4 position;
+
+            void main()
+            {
+                gl_Position = position;
+            }
+        );
+
+        const std::string fragmentShaderSource = SHADER_SOURCE
+        (
+            precision highp float;
+
+            void main()
+            {
+                gl_FragColor = vec4(1.0, 0.0, 0.0, 1.0);
+            }
+        );
+
+        mProgram = compileProgram(vertexShaderSource, fragmentShaderSource);
+        if (mProgram == 0)
+        {
+            FAIL() << "shader compilation failed.";
+        }
+    }
+
+    virtual void TearDown()
+    {
+        glDeleteProgram(mProgram);
+
+        ANGLETest::TearDown();
+    }
+
+    GLuint mProgram;
+};
+
+TEST_F(ClearTest, clear_issue)
+{
+    EXPECT_GL_NO_ERROR();
+
+    glEnable(GL_DEPTH_TEST);
+    glDepthFunc(GL_LEQUAL);
+
+    glClearColor(0.0, 1.0, 0.0, 1.0);
+    glClearDepthf(0.0);
+    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+    EXPECT_GL_NO_ERROR();
+
+    GLuint fbo;
+    glGenFramebuffers(1, &fbo);
+    glBindFramebuffer(GL_FRAMEBUFFER, fbo);
+
+    GLuint rbo;
+    glGenRenderbuffers(1, &rbo);
+    glBindRenderbuffer(GL_RENDERBUFFER, rbo);
+    glRenderbufferStorage(GL_RENDERBUFFER, GL_RGB565, 16, 16);
+
+    EXPECT_GL_NO_ERROR();
+
+    glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_RENDERBUFFER, rbo);
+
+    EXPECT_GL_NO_ERROR();
+
+    glClearColor(1.0f, 0.0f, 0.0f, 1.0f);
+    glClearDepthf(1.0f);
+    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+    EXPECT_GL_NO_ERROR();
+
+    glBindFramebuffer(GL_FRAMEBUFFER, 0);
+    glBindBuffer(GL_ARRAY_BUFFER, 0);
+
+    drawQuad(mProgram, "position", 0.5f);
+
+    EXPECT_PIXEL_EQ(0, 0, 0, 255, 0, 255);
+}