fix accidental C modulo semantics on integer-valued operations

(e.g. caused C<length("abc") % -10> to return 3 rather than -7)

p4raw-id: //depot/perl@4428

diff --git a/op.c b/op.c
index f38b26c..7fae9f7 100644 (file)
--- a/op.c
+++ b/op.c
@@ -2112,8 +2112,12 @@ Perl_fold_constants(pTHX_ register OP *o)
        return o;
 
     if (!(PL_hints & HINT_INTEGER)) {
-       if (type == OP_DIVIDE || !(o->op_flags & OPf_KIDS))
+       if (type == OP_MODULO
+           || type == OP_DIVIDE
+           || !(o->op_flags & OPf_KIDS))
+       {
            return o;
+       }
 
        for (curop = ((UNOP*)o)->op_first; curop; curop = curop->op_sibling) {
            if (curop->op_type == OP_CONST) {

diff --git a/t/op/int.t b/t/op/int.t
index eb060ac..c01c12a 100755 (executable)
--- a/t/op/int.t
+++ b/t/op/int.t
@@ -1,8 +1,6 @@
 #!./perl
 
-# $RCSfile: int.t,v $$Revision: 4.1 $$Date: 92/08/07 18:28:00 $
-
-print "1..4\n";
+print "1..6\n";
 
 # compile time evaluation
 
@@ -15,3 +13,12 @@ if (int(-1.234) == -1) {print "ok 2\n";} else {print "not ok 2\n";}
 $x = 1.234;
 if (int($x) == 1) {print "ok 3\n";} else {print "not ok 3\n";}
 if (int(-$x) == -1) {print "ok 4\n";} else {print "not ok 4\n";}
+
+$x = length("abc") % -10;
+print $x == -7 ? "ok 5\n" : "# expected -7, got $x\nnot ok 5\n";
+
+{
+    use integer;
+    $x = length("abc") % -10;
+    print $x == 3 ? "ok 6\n" : "# expected 3, got $x\nnot ok 6\n";
+}