Let the regex parser decide if we have a special pattern or not.

Message-ID: <9b18b3110701081546n2c3f19acy29adc0d233bb848c@mail.gmail.com>

p4raw-id: //depot/perl@29730

1 files changed, 5 insertions, 0 deletions

diff --git a/regcomp.c b/regcomp.c
index 8772237205..c1c141a0ab 100644
--- a/regcomp.c
+++ b/regcomp.c
@@ -4582,6 +4582,11 @@ reStudy:
         r->paren_names = (HV*)SvREFCNT_inc(RExC_paren_names);
     else
         r->paren_names = NULL;
+    if (r->prelen == 3 && strEQ("\\s+", r->precomp))
+	r->extflags |= RXf_WHITE;
+    else if (r->prelen == 1 && r->precomp[0] == '^')
+        r->extflags |= RXf_START_ONLY;
+
 #ifdef DEBUGGING
     if (RExC_paren_names) {
         ri->name_list_idx = add_data( pRExC_state, 1, "p" );