Add memBEGINPs() to core and use it

This macro is like memBEGINs(), but the 'P' signifies we want a proper
substring, meaning that the 2nd string parameter must not be the entire
first parameter.

1 files changed, 16 insertions, 9 deletions

diff --git a/toke.c b/toke.c
index 5593b6fd9f..734b02cdb6 100644
--- a/toke.c
+++ b/toke.c
@@ -2103,8 +2103,10 @@ S_force_word(pTHX_ char *start, int token, int check_keyword, int allow_pack)
 	if (check_keyword) {
 	  char *s2 = PL_tokenbuf;
 	  STRLEN len2 = len;
-	  if (allow_pack && len > 6 && strBEGINs(s2, "CORE::"))
-	    s2 += 6, len2 -= 6;
+	  if (allow_pack && memBEGINPs(s2, len, "CORE::")) {
+	    s2 += sizeof("CORE::") - 1;
+            len2 -= sizeof("CORE::") - 1;
+          }
 	  if (keyword(s2, len2, 0))
 	    return start;
 	}
@@ -5369,7 +5371,9 @@ Perl_yylex(pTHX)
 	    }
 	    if (PL_parser->in_pod) {
 		/* Incest with pod. */
-		if (*s == '=' && strBEGINs(s, "=cut") && !isALPHA(s[4])) {
+                if (    memBEGINPs(s, (STRLEN) (PL_bufend - s), "=cut")
+                    && !isALPHA(s[4]))
+                {
                     SvPVCLEAR(PL_linestr);
 		    PL_oldoldbufptr = PL_oldbufptr = s = PL_linestart = SvPVX(PL_linestr);
 		    PL_bufend = SvPVX(PL_linestr) + SvCUR(PL_linestr);
@@ -7950,14 +7954,17 @@ Perl_yylex(pTHX)
 		char *p = s;
                 SSize_t s_off = s - SvPVX(PL_linestr);
 
-		if ((PL_bufend - p) >= 3
-                    && strBEGINs(p, "my") && isSPACE(*(p + 2)))
+                if (   memBEGINPs(p, (STRLEN) (PL_bufend - p), "my")
+                    && isSPACE(*(p + 2)))
                 {
-		    p += 2;
+                    p += 2;
                 }
-		else if ((PL_bufend - p) >= 4
-                         && strBEGINs(p, "our") && isSPACE(*(p + 3)))
-		    p += 3;
+                else if (   memBEGINPs(p, (STRLEN) (PL_bufend - p), "our")
+                         && isSPACE(*(p + 3)))
+                {
+                    p += 3;
+                }
+
 		p = skipspace(p);
                 /* skip optional package name, as in "for my abc $x (..)" */
 	        if (isIDFIRST_lazy_if_safe(p, PL_bufend, UTF)) {