don't taint $$ determined by getpid()

Reading $$ in a tainted expression was tainting the internal sv_setiv()
on $$.  Since the value being set came directly from getpid(), it's
always safe, so override the tainting there.  Fixes [perl #109688].

1 files changed, 8 insertions, 1 deletions

diff --git a/t/op/taint.t b/t/op/taint.t
index 0b626f340c..1b754399f9 100644
--- a/t/op/taint.t
+++ b/t/op/taint.t
@@ -17,7 +17,7 @@ BEGIN {
 use strict;
 use Config;
 
-plan tests => 791;
+plan tests => 793;
 
 $| = 1;
 
@@ -2176,6 +2176,13 @@ for(1,2) {
 }
 pass("no death when TARG of ref is tainted");
 
+# $$ should not be tainted by being read in a tainted expression.
+{
+    isnt_tainted $$, "PID not tainted initially";
+    my $x = $ENV{PATH}.$$;
+    isnt_tainted $$, "PID not tainted when read in tainted expression";
+}
+
 {
     use feature 'fc';
     use locale;