CopyTextureCHROMIUM: Validate the texture target enums first.

INVALID_ENUM should be generated before any INVALID_VALUE errors based
on the texture state.

BUG=angleproject:1932

Change-Id: If74440602d56b1a86fa24ff87c38d2b0dec2bfb2
Reviewed-on: https://chromium-review.googlesource.com/744448
Commit-Queue: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
diff --git a/src/libANGLE/validationES2.cpp b/src/libANGLE/validationES2.cpp
index 13e65d2..af93da2 100644
--- a/src/libANGLE/validationES2.cpp
+++ b/src/libANGLE/validationES2.cpp
@@ -306,30 +306,39 @@
     return true;
 }
 
-bool IsValidCopyTextureDestinationTarget(Context *context, GLenum textureType, GLenum target)
+bool IsValidCopyTextureDestinationTargetEnum(Context *context, GLenum target)
 {
     switch (target)
     {
         case GL_TEXTURE_2D:
-            return textureType == GL_TEXTURE_2D;
-
         case GL_TEXTURE_CUBE_MAP_POSITIVE_X:
         case GL_TEXTURE_CUBE_MAP_NEGATIVE_X:
         case GL_TEXTURE_CUBE_MAP_POSITIVE_Y:
         case GL_TEXTURE_CUBE_MAP_NEGATIVE_Y:
         case GL_TEXTURE_CUBE_MAP_POSITIVE_Z:
         case GL_TEXTURE_CUBE_MAP_NEGATIVE_Z:
-            return textureType == GL_TEXTURE_CUBE_MAP;
+            return true;
 
         case GL_TEXTURE_RECTANGLE_ANGLE:
-            return textureType == GL_TEXTURE_RECTANGLE_ANGLE &&
-                   context->getExtensions().textureRectangle;
+            return context->getExtensions().textureRectangle;
 
         default:
             return false;
     }
 }
 
+bool IsValidCopyTextureDestinationTarget(Context *context, GLenum textureType, GLenum target)
+{
+    if (IsCubeMapTextureTarget(target))
+    {
+        return textureType == GL_TEXTURE_CUBE_MAP;
+    }
+    else
+    {
+        return textureType == target;
+    }
+}
+
 bool IsValidCopyTextureSourceTarget(Context *context, GLenum target)
 {
     switch (target)
@@ -3871,6 +3880,12 @@
         return false;
     }
 
+    if (!IsValidCopyTextureDestinationTargetEnum(context, destTarget))
+    {
+        ANGLE_VALIDATION_ERR(context, InvalidEnum(), InvalidTextureTarget);
+        return false;
+    }
+
     const Texture *dest = context->getTexture(destId);
     if (dest == nullptr)
     {
@@ -3993,6 +4008,12 @@
         return false;
     }
 
+    if (!IsValidCopyTextureDestinationTargetEnum(context, destTarget))
+    {
+        ANGLE_VALIDATION_ERR(context, InvalidEnum(), InvalidTextureTarget);
+        return false;
+    }
+
     const Texture *dest = context->getTexture(destId);
     if (dest == nullptr)
     {