GenerateMipmaps should generate INVALID_OPERATION in ES 2.0 with EXT_sRGB

src/libANGLE/validationES2.cpp

@@ -6129,11 +6129,9 @@ bool ValidateGenerateMipmap(Context *context, TextureType target)
         return false;
     }
 
-    // ES3 and WebGL grant mipmap generation for sRGBA (with alpha) textures but GL_EXT_sRGB does
-    // not.  Differentiate the ES3 format from the extension format by checking if the format is
-    // sized, GL_EXT_sRGB does not add any sized formats.
-    bool supportsSRGBMipmapGeneration = context->getExtensions().webglCompatibility;
-    if (!supportsSRGBMipmapGeneration && !format.sized && format.colorEncoding == GL_SRGB)
+    // According to the OpenGL extension spec EXT_sRGB.txt, EXT_SRGB is based on ES 2.0 and
+    // generateMipmap is not allowed if texture format is SRGB_EXT or SRGB_ALPHA_EXT.
+    if (context->getClientVersion() < Version(3, 0) && format.colorEncoding == GL_SRGB)
     {
         ANGLE_VALIDATION_ERR(context, InvalidOperation(), GenerateMipmapNotAllowed);
         return false;

src/tests/gl_tests/SRGBTextureTest.cpp

@@ -66,6 +66,8 @@ class SRGBTextureTest : public ANGLETest
     GLint mTextureLocation = -1;
 };
 
+// GenerateMipmaps should generate INVALID_OPERATION in ES 2.0 / WebGL 1.0 with EXT_sRGB.
+// https://bugs.chromium.org/p/chromium/issues/detail?id=769989
 TEST_P(SRGBTextureTest, SRGBValidation)
 {
     // TODO(fjhenigman): Figure out why this fails on Ozone Intel.
@@ -87,7 +89,14 @@ TEST_P(SRGBTextureTest, SRGBValidation)
         EXPECT_GL_NO_ERROR();
 
         glGenerateMipmap(GL_TEXTURE_2D);
-        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
+        if (getClientMajorVersion() < 3)
+        {
+            EXPECT_GL_ERROR(GL_INVALID_OPERATION);
+        }
+        else
+        {
+            EXPECT_GL_NO_ERROR();
+        }
     }
     else
     {
@@ -118,7 +127,14 @@ TEST_P(SRGBTextureTest, SRGBAValidation)
         EXPECT_GL_NO_ERROR();
 
         glGenerateMipmap(GL_TEXTURE_2D);
-        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
+        if (getClientMajorVersion() < 3)
+        {
+            EXPECT_GL_ERROR(GL_INVALID_OPERATION);
+        }
+        else
+        {
+            EXPECT_GL_NO_ERROR();
+        }
     }
     else
     {