diff -Nur Mail-SpamAssassin-3.3.2.orig/lib/Mail/SpamAssassin/AsyncLoop.pm Mail-SpamAssassin-3.3.2/lib/Mail/SpamAssassin/AsyncLoop.pm
--- Mail-SpamAssassin-3.3.2.orig/lib/Mail/SpamAssassin/AsyncLoop.pm	2011-06-06 17:59:17.000000000 -0600
+++ Mail-SpamAssassin-3.3.2/lib/Mail/SpamAssassin/AsyncLoop.pm	2014-01-04 12:06:42.841484361 -0700
@@ -360,7 +360,15 @@
     }
     $now = time;  # capture new timestamp, after possible sleep in 'select'
 
-    while (my($key,$ent) = each %$pending) {
+    # A callback routine may generate another DNS query, which may insert
+    # an entry into the %$pending hash thus invalidating the each() context.
+    # So, make sure that callbacks are not called while the each() context
+    # is open, or avoid using each().  [Bug 6937]
+    #
+    # while (my($key,$ent) = each %$pending) {
+    foreach my $key (keys %$pending) {
+      my $ent = $pending->{$key};
+
       my $id = $ent->{id};
       if (defined $ent->{poll_callback}) {  # call a "poll_callback" if exists
         # be nice, provide fresh info to a callback routine
@@ -448,7 +456,8 @@
   my $pending = $self->{pending_lookups};
   my $foundcnt = 0;
   my $now = time;
-  while (my($key,$ent) = each %$pending) {
+  foreach my $key (keys %$pending) {
+    my $ent = $pending->{$key};
     dbg("async: aborting after %.3f s, %s: %s",
         $now - $ent->{start_time},
         (defined $ent->{timeout_initial} &&
diff -Nur Mail-SpamAssassin-3.3.2.orig/lib/Mail/SpamAssassin/Conf/Parser.pm Mail-SpamAssassin-3.3.2/lib/Mail/SpamAssassin/Conf/Parser.pm
--- Mail-SpamAssassin-3.3.2.orig/lib/Mail/SpamAssassin/Conf/Parser.pm	2011-06-06 17:59:17.000000000 -0600
+++ Mail-SpamAssassin-3.3.2/lib/Mail/SpamAssassin/Conf/Parser.pm	2014-01-04 12:07:42.897360312 -0700
@@ -1248,7 +1248,7 @@
   my $safere = $re;
   my $mods = '';
   local ($1,$2);
-  if ($re =~ s/^m{//) {
+  if ($re =~ s/^m\{//) {
     $re =~ s/}([a-z]*)$//; $mods = $1;
   }
   elsif ($re =~ s/^m\(//) {
diff -Nur Mail-SpamAssassin-3.3.2.orig/lib/Mail/SpamAssassin/DnsResolver.pm Mail-SpamAssassin-3.3.2/lib/Mail/SpamAssassin/DnsResolver.pm
--- Mail-SpamAssassin-3.3.2.orig/lib/Mail/SpamAssassin/DnsResolver.pm	2011-06-06 17:59:17.000000000 -0600
+++ Mail-SpamAssassin-3.3.2/lib/Mail/SpamAssassin/DnsResolver.pm	2014-01-04 12:09:17.797584164 -0700
@@ -440,10 +440,16 @@
     { my $timer;  # collects timestamp when variable goes out of scope
       if (!defined($timeout) || $timeout > 0)
         { $timer = $self->{main}->time_method("poll_dns_idle") }
+      $! = 0;
       ($nfound, $timeleft) = select($rout=$rin, undef, undef, $timeout);
     }
     if (!defined $nfound || $nfound < 0) {
-      warn "dns: select failed: $!";
+      if ($!) { warn "dns: select failed: $!\n" }
+      else    { info("dns: select interrupted") }
+      return;
+    } elsif (!$nfound) {
+      if (!defined $timeout) { warn("dns: select returned empty-handed\n") }
+      elsif ($timeout > 0) { dbg("dns: select timed out %.3f s", $timeout) }
       return;
     }
 
diff -Nur Mail-SpamAssassin-3.3.2.orig/lib/Mail/SpamAssassin/Message.pm Mail-SpamAssassin-3.3.2/lib/Mail/SpamAssassin/Message.pm
--- Mail-SpamAssassin-3.3.2.orig/lib/Mail/SpamAssassin/Message.pm	2011-06-06 17:59:17.000000000 -0600
+++ Mail-SpamAssassin-3.3.2/lib/Mail/SpamAssassin/Message.pm	2014-01-04 12:10:02.247752269 -0700
@@ -566,7 +566,7 @@
   while (my $part = shift @toclean) {
     # bug 5557: windows requires tmp file be closed before it can be rm'd
     if (ref $part->{'raw'} eq 'GLOB') {
-      close($part->{'raw'})  or die "error closing input file: $!";
+      close($part->{'raw'})  or warn "error closing input file: $!";
     }
 
     # bug 5858: avoid memory leak with deep MIME structure
diff -Nur Mail-SpamAssassin-3.3.2.orig/lib/Mail/SpamAssassin/PerMsgStatus.pm Mail-SpamAssassin-3.3.2/lib/Mail/SpamAssassin/PerMsgStatus.pm
--- Mail-SpamAssassin-3.3.2.orig/lib/Mail/SpamAssassin/PerMsgStatus.pm	2011-06-06 17:59:17.000000000 -0600
+++ Mail-SpamAssassin-3.3.2/lib/Mail/SpamAssassin/PerMsgStatus.pm	2014-01-04 12:12:03.585481321 -0700
@@ -420,8 +420,8 @@
       }
     }
 
-    # ignore tests with 0 score in this scoreset
-    next if ($scores->{$test} == 0);
+    # ignore tests with 0 score (or undefined) in this scoreset
+    next if !$scores->{$test};
 
     # Go ahead and add points to the proper locations
     if (!$self->{conf}->maybe_header_only ($test)) {
@@ -1252,13 +1252,12 @@
               my $arg = (shift || ",");
               my $line = '';
               foreach my $test (sort @{$self->{test_names_hit}}) {
-                if (!$line) {
-                  $line .= $test . "=" . $self->{conf}->{scores}->{$test};
-                } else {
-                  $line .= $arg . $test . "=" . $self->{conf}->{scores}->{$test};
-                }
+                my $score = $self->{conf}->{scores}->{$test};
+                $score = '0'  if !defined $score;
+                $line .= $arg  if $line ne '';
+                $line .= $test . "=" . $score;
               }
-              $line ? $line : 'none';
+              $line ne '' ? $line : 'none';
             },
 
             PREVIEW => sub { $self->get_content_preview() },
diff -Nur Mail-SpamAssassin-3.3.2.orig/lib/Mail/SpamAssassin/Util.pm Mail-SpamAssassin-3.3.2/lib/Mail/SpamAssassin/Util.pm
--- Mail-SpamAssassin-3.3.2.orig/lib/Mail/SpamAssassin/Util.pm	2011-06-06 17:59:17.000000000 -0600
+++ Mail-SpamAssassin-3.3.2/lib/Mail/SpamAssassin/Util.pm	2014-01-04 12:12:26.262056907 -0700
@@ -1585,7 +1585,7 @@
   elsif ($re =~ s/^m{//) {              # m{foo/bar}
     $delim = '}';
   }
-  elsif ($re =~ s/^m\(//) {             # m(foo/bar)
+  elsif ($re =~ s/^m\{//) {             # m{foo/bar}
     $delim = ')';
   }
   elsif ($re =~ s/^m<//) {              # m<foo/bar>