fix bug #57042 - preserve $^R across TRIE matches

2 files changed, 23 insertions, 4 deletions

diff --git a/regexec.c b/regexec.c
index 6c0923fc8b..f959121b81 100644
--- a/regexec.c
+++ b/regexec.c
@@ -3003,7 +3003,7 @@ S_regmatch(pTHX_ regmatch_info *reginfo, regnode *prog)
 		    if ( got_wordnum ) {
 			if ( ! ST.accepted ) {
 			    ENTER;
-			    /* SAVETMPS; */ /* XXX is this necessary? dmq */
+			    SAVETMPS; /* XXX is this necessary? dmq */
 			    bufflen = TRIE_INITAL_ACCEPT_BUFFLEN;
 			    sv_accept_buff=newSV(bufflen *
 					    sizeof(reg_trie_accepted) - 1);
@@ -3222,6 +3222,9 @@ S_regmatch(pTHX_ regmatch_info *reginfo, regnode *prog)
 	    }
 	    /* NOTREACHED */
         case TRIE_next:
+	    /* we dont want to throw this away, see bug 57042*/
+	    if (oreplsv != GvSV(PL_replgv))
+		sv_setsv(oreplsv, GvSV(PL_replgv));
             FREETMPS;
 	    LEAVE;
 	    sayYES;
diff --git a/t/op/pat.t b/t/op/pat.t
index 040c67150f..aa275bd4f4 100755
--- a/t/op/pat.t
+++ b/t/op/pat.t
@@ -13,7 +13,7 @@ sub run_tests;
 
 $| = 1;
 
-my $EXPECTED_TESTS = 3864;  # Update this when adding/deleting tests.
+my $EXPECTED_TESTS = 3865;  # Update this when adding/deleting tests.
 
 BEGIN {
     chdir 't' if -d 't';
@@ -2935,7 +2935,7 @@ sub run_tests {
 
         SKIP: {
             our @stack = ();
-            my @expect = qw (
+            my @expect = qw(
                 stuff1
                 stuff2
                 <stuff1>and<stuff2>
@@ -4083,7 +4083,23 @@ sub run_tests {
         utf8::upgrade $s;
         ok "aaa" =~ /$s/;
     }
-
+    {
+        local $BugId = '57042';
+	local $Message = "Check if tree logic breaks \$^R";
+	my $cond_re = qr/\s*
+	    \s* (?:
+		   \( \s* A  (?{1})
+		 | \( \s* B  (?{2})
+	       )
+	   /x;
+	my @res;
+	for my $line ("(A)","(B)") {
+	   if ($line =~ m/$cond_re/) {
+	       push @res, $^R ? "#$^R" : "UNDEF";
+	   }
+	}
+	iseq "@res","#1 #2";
+    }
     #
     # This should be the last test.
     #