Add debug code to test IPC::Open3::spawn_with_handles() on *nix.

This allows testing of the (normally) Win32 and OS/2 specific code paths in
IPC::Open3::open3().

diff --git a/ext/IPC-Open3/lib/IPC/Open3.pm b/ext/IPC-Open3/lib/IPC/Open3.pm
index b1acfd0..4513fff 100644 (file)
--- a/ext/IPC-Open3/lib/IPC/Open3.pm
+++ b/ext/IPC-Open3/lib/IPC/Open3.pm
@@ -194,7 +194,8 @@ sub xfileno {
     return fileno $_[0];
 }
 
-use constant DO_SPAWN => $^O eq 'os2' || $^O eq 'MSWin32';
+use constant FORCE_DEBUG_SPAWN => 0;
+use constant DO_SPAWN => $^O eq 'os2' || $^O eq 'MSWin32' || FORCE_DEBUG_SPAWN;
 
 sub _open3 {
     local $Me = shift;
@@ -400,13 +401,33 @@ sub spawn_with_handles {
     unless ($^O eq 'MSWin32') {
        # Stderr may be redirected below, so we save the err text:
        foreach $fd (@$close_in_child) {
+           next unless fileno $fd;
            fcntl($fd, Fcntl::F_SETFD(), 1) or push @errs, "fcntl $fd: $!"
                unless $saved{fileno $fd}; # Do not close what we redirect!
        }
     }
 
     unless (@errs) {
-       $pid = eval { system 1, @_ }; # 1 == P_NOWAIT
+       if (FORCE_DEBUG_SPAWN) {
+           pipe my $r, my $w or die "Pipe failed: $!";
+           $pid = fork;
+           die "Fork failed: $!" unless defined $pid;
+           if (!$pid) {
+               { no warnings; exec @_ }
+               print $w 0 + $!;
+               close $w;
+               require POSIX;
+               POSIX::_exit(255);
+           }
+           close $w;
+           my $bad = <$r>;
+           if (defined $bad) {
+               $! = $bad;
+               undef $pid;
+           }
+       } else {
+           $pid = eval { system 1, @_ }; # 1 == P_NOWAIT
+       }
        push @errs, "IO::Pipe: Can't spawn-NOWAIT: $!" if !$pid || $pid < 0;
     }