Change SvTAIL() to check that both SVpbm_TAIL|SVpbm_VALID are true.

SVpbm_VALID is the same bit value is SVf_IVisUV, which means that
PVBMs can't actually ever be IOK. Therefore move BmUSEFUL() into the
IV union, and save one I32 per PVBM.

p4raw-id: //depot/perl@29518

1 files changed, 1 insertions, 0 deletions

diff --git a/util.c b/util.c
index 358af393a3..fff8c8a7d9 100644
--- a/util.c
+++ b/util.c
@@ -493,6 +493,7 @@ Perl_fbm_compile(pTHX_ SV *sv, U32 flags)
     if (len == 0)		/* TAIL might be on a zero-length string. */
 	return;
     SvUPGRADE(sv, SVt_PVBM);
+    SvIOK_off(sv);
     if (len > 2) {
 	const unsigned char *sb;
 	const U8 mlen = (len>255) ? 255 : (U8)len;