C<new SelectSaver $fh> doesn't always restore

This is a bug report for perl from spider@Orb.Nashua.NH.US,

If you're lucky enough to get a signal (such as ALRM) which is handled
with die() while in a SelectSaver->new($fh) call, your previous output
filehandle is not restored.  It violates the basic rule of 'save and
restore' handling, in that it modifies the state it wants to restore
I<before> it has ensured that the prior state will be restored.  Patch:

p5p-msgid: 199703291906.OAA07232@Orb.Nashua.NH.US

diff --git a/lib/SelectSaver.pm b/lib/SelectSaver.pm
index 4c764be..5f56922 100644 (file)
--- a/lib/SelectSaver.pm
+++ b/lib/SelectSaver.pm
@@ -38,8 +38,10 @@ use Symbol;
 
 sub new {
     @_ >= 1 && @_ <= 2 or croak 'usage: new SelectSaver [FILEHANDLE]';
-    my $fh = (@_ > 1) ? (select qualify($_[1], caller)) : select;
-    bless [$fh], $_[0];
+    my $fh = select;
+    my $self = bless [$fh], $_[0];
+    select qualify($_[1], caller) if @_ > 1;
+    $self;
 }
 
 sub DESTROY {