mesa: check that internalformat of CopyTexImage*D is not 1, 2, 3, 4

The piglit copyteximage check has recently been augmented to test this, but
apparently it hasn't been fixed in Mesa so far.

This language also already appears in the OpenGL 2.1 spec (Ian).

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>

src/mesa/main/teximage.c

@@ -2247,6 +2247,22 @@ copytexture_error_check( struct gl_context *ctx, GLuint dimensions,
                      _mesa_enum_to_string(internalFormat));
          return GL_TRUE;
       }
+   } else {
+      /*
+       * Section 8.6 (Alternate Texture Image Specification Commands) of the
+       * OpenGL 4.5 (Compatibility Profile) spec says:
+       *
+       *     "Parameters level, internalformat, and border are specified using
+       *     the same values, with the same meanings, as the corresponding
+       *     arguments of TexImage2D, except that internalformat may not be
+       *     specified as 1, 2, 3, or 4."
+       */
+      if (internalFormat >= 1 && internalFormat <= 4) {
+         _mesa_error(ctx, GL_INVALID_ENUM,
+                     "glCopyTexImage%dD(internalFormat=%d)", dimensions,
+                     internalFormat);
+         return GL_TRUE;
+      }
    }
 
    baseFormat = _mesa_base_tex_format(ctx, internalFormat);