[PATCH] preserving message on croak, reduce _waits

[Chip Salzenberg]

The below patch persuades ->recv to preserve a message unchanged if it
ends with a newline already.
It also, orthogonally, prevents unnecessary calls to _wait.  The
performance effect of this change depends on how many of your recvs
wait; in my code, at least, few of them do.

diff --git lib/AnyEvent.pm lib/AnyEvent.pm
index df1f159..a0f7801 100644
--- lib/AnyEvent.pm
+++ lib/AnyEvent.pm
@@ -1765,9 +1765,13 @@ sub _wait {
 }
 
 sub recv {
-   $_[0]->_wait;
+   $_[0]->_wait unless $_[0]{_ae_sent};
 
-   Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};
+   if ($_[0]{_ae_croak}) {
+       for ($_[0]{_ae_croak}) {
+           ref() || /\n\z/ ? die $_ : Carp::croak($_)
+       }
+   }
    wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]
 }