[perl #28938] split could leave an array without &PL_sv_undef

 in the unused elements

p4raw-id: //depot/perl@22774

diff --git a/pp.c b/pp.c
index 1a35902..a3e56d3 100644 (file)
--- a/pp.c
+++ b/pp.c
@@ -4636,7 +4636,7 @@ PP(pp_split)
            if (TOPs && !make_mortal)
                sv_2mortal(TOPs);
            iters--;
-           SP--;
+           *SP-- = &PL_sv_undef;
        }
     }
 

diff --git a/t/op/split.t b/t/op/split.t
index 957da24..31a2f51 100755 (executable)
--- a/t/op/split.t
+++ b/t/op/split.t
@@ -6,7 +6,7 @@ BEGIN {
     require './test.pl';
 }
 
-plan tests => 54;
+plan tests => 55;
 
 $FS = ':';
 
@@ -289,3 +289,16 @@ ok(@ary == 3 &&
     $n = @a = split /,/,$p;
     is ($n, 0, '#21765 - pmreplroot hack used to return undef for 0 iters');
 }
+
+{
+    # [perl #28938]
+    # assigning off the end of the array after a split could leave garbage
+    # in the inner elements
+
+    my $x;
+    @a = split /,/, ',,,,,';
+    $a[3]=1;
+    $x = \$a[2];
+    is (ref $x, 'SCALAR', '#28938 - garbage after extend');
+}
+