Clean up in implementation of f_is_geom()/f_is_bitfield()/f_is_enum()

macros.

It does not fixes any bugs in 4.0. But it prevents from future error in
any bugfixes that may use these macros. Also after merging into 4.1 tree
this cleanup will fix bug #7884 "Able to add invalid unique index on
TIMESTAMP prefix".


sql/field.h:
  Since FIELDFLAG_INTERVAL, FIELDFLAG_BITFIELD, FIELDFLAG_BLOB and
  FIELDFLAG_GEOM flags occupy the same space as number of decimals for
  FIELDFLAG_NUMBER fields, it is safer to check in "f_is_geom()"-type
  macros that we have non-number field, like we already do in f_is_blob()
  macro.

sql/field.h

@@ -1101,10 +1101,10 @@ bool test_if_int(const char *str,int length);
 #define FIELDFLAG_NUMBER		2
 #define FIELDFLAG_ZEROFILL		4
 #define FIELDFLAG_PACK			120	// Bits used for packing
-#define FIELDFLAG_INTERVAL		256
-#define FIELDFLAG_BITFIELD		512	// mangled with dec!
-#define FIELDFLAG_BLOB			1024	// mangled with dec!
-#define FIELDFLAG_GEOM			2048
+#define FIELDFLAG_INTERVAL		256     // mangled with decimals!
+#define FIELDFLAG_BITFIELD		512	// mangled with decimals!
+#define FIELDFLAG_BLOB			1024	// mangled with decimals!
+#define FIELDFLAG_GEOM			2048    // mangled with decimals!
 #define FIELDFLAG_LEFT_FULLSCREEN	8192
 #define FIELDFLAG_RIGHT_FULLSCREEN	16384
 #define FIELDFLAG_FORMAT_NUMBER		16384	// predit: ###,,## in output
@@ -1128,10 +1128,10 @@ bool test_if_int(const char *str,int length);
 #define f_decimals(x)		((uint8) (((x) >> FIELDFLAG_DEC_SHIFT) & FIELDFLAG_MAX_DEC))
 #define f_is_alpha(x)		(!f_is_num(x))
 #define f_is_binary(x)		((x) & FIELDFLAG_BINARY)
-#define f_is_enum(x)	((x) & FIELDFLAG_INTERVAL)
-#define f_is_bitfield(x)	((x) & FIELDFLAG_BITFIELD)
+#define f_is_enum(x)            (((x) & (FIELDFLAG_INTERVAL | FIELDFLAG_NUMBER)) == FIELDFLAG_INTERVAL)
+#define f_is_bitfield(x)        (((x) & (FIELDFLAG_BITFIELD | FIELDFLAG_NUMBER)) == FIELDFLAG_BITFIELD)
 #define f_is_blob(x)		(((x) & (FIELDFLAG_BLOB | FIELDFLAG_NUMBER)) == FIELDFLAG_BLOB)
-#define f_is_geom(x)		((x) & FIELDFLAG_GEOM)
+#define f_is_geom(x)		(((x) & (FIELDFLAG_GEOM | FIELDFLAG_NUMBER)) == FIELDFLAG_GEOM)
 #define f_is_equ(x)		((x) & (1+2+FIELDFLAG_PACK+31*256))
 #define f_settype(x)		(((int) x) << FIELDFLAG_PACK_SHIFT)
 #define f_maybe_null(x)		(x & FIELDFLAG_MAYBE_NULL)