#define DISP_TABLE_P(obj) \
(CHAR_TABLE_P (obj) \
- && XCHAR_TABLE (obj)->purpose == Qdisplay_table \
+ && EQ (XCHAR_TABLE (obj)->purpose, Qdisplay_table) \
&& CHAR_TABLE_EXTRA_SLOTS (XCHAR_TABLE (obj)) == DISP_TABLE_EXTRA_SLOTS)
#define DISP_TABLE_EXTRA_SLOTS 6