default to CORE::warn in $SIG{__WARN__} handlers

As with CORE::die and $SIG{__DIE__}, it turns out CORE::warn is
safe to use inside $SIG{__WARN__} handlers without triggering
infinite recursion.  So fall back to reusing CORE::warn instead
of creating a new sub.

1 files changed, 1 insertions, 1 deletions

diff --git a/lib/PublicInbox/InboxWritable.pm b/lib/PublicInbox/InboxWritable.pm
index 31eb3f15..b1d5caf5 100644
--- a/lib/PublicInbox/InboxWritable.pm
+++ b/lib/PublicInbox/InboxWritable.pm
@@ -292,7 +292,7 @@ sub warn_ignore {
 
 # this expects to be RHS in this assignment: "local $SIG{__WARN__} = ..."
 sub warn_ignore_cb {
-        my $cb = $SIG{__WARN__} // sub { print STDERR @_ };
+        my $cb = $SIG{__WARN__} // \&CORE::warn;
         sub {
                 return if warn_ignore(@_);
                 $cb->(@_);