From: David Mitchell <davem@iabyn.com>
Date: Mon, 11 Jan 2010 21:42:07 +0000 (+0000)
Subject: fix for [perl #61976] Errno ($!) not evaluated to a error message string
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=0097b436152452e403cc71b4f1a1cfd30ec0ba1a;p=p5sagit%2Fp5-mst-13.2.git

fix for [perl #61976] Errno ($!) not evaluated to a error message string
(5.10.0 in taint mode)

Change 27176 / 2a509ed3c095f7d712013e653f68821f6bb2d6db fixed a taint
bug, which as a side effect, meant that $! used within a tainted expression
failed to have a string value.

This quick fix just makes sure the POK flag is set (prior to it being
shifted back to pPOK).
---

diff --git a/mg.c b/mg.c
index fb91325..ddfc2ff 100644
--- a/mg.c
+++ b/mg.c
@@ -1048,6 +1048,7 @@ Perl_magic_get(pTHX_ SV *sv, MAGIC *mg)
 	else
 #endif
 	sv_setpv(sv, errno ? Strerror(errno) : "");
+	SvPOK_on(sv);	/* may have got removed during taint processing */
 	RESTORE_ERRNO;
 	}
 #endif
diff --git a/t/op/taint.t b/t/op/taint.t
index 796b6fa..161073d 100644
--- a/t/op/taint.t
+++ b/t/op/taint.t
@@ -17,7 +17,7 @@ use Config;
 use File::Spec::Functions;
 
 BEGIN { require './test.pl'; }
-plan tests => 301;
+plan tests => 302;
 
 $| = 1;
 
@@ -1308,6 +1308,17 @@ foreach my $ord (78, 163, 256) {
     ok(tainted($zz), "pack a*a* preserves tainting");
 }
 
+# Bug RT #61976 tainted $! would show numeric rather than string value
+
+{
+    my $tainted_path = substr($^X,0,0) . "/no/such/file";
+    my $err;
+    # $! is used in a tainted expression, so gets tainted
+    open my $fh, $tainted_path or $err= "$!";
+    unlike($err, qr/^\d+$/, 'tainted $!');
+}
+
+
 # This may bomb out with the alarm signal so keep it last
 SKIP: {
     skip "No alarm()"  unless $Config{d_alarm};