kill some further mallocs and add note to remind us not to add them back

Conflicts:
	pdns/dnsparser.cc

Author: ahupowerdns

pdns/dnsparser.cc

@@ -437,6 +437,7 @@ void PacketReader::getLabelFromContent(const vector<uint8_t>& content, uint16_t&
     throw MOADNSException("Loop");
 
   int pos = frompos;
+  // it is tempting to call reserve on ret, but it turns out it creates a malloc/free storm in the loop
   for(;;) {
     unsigned char labellen=content.at(frompos++);
 
@@ -455,7 +456,7 @@ void PacketReader::getLabelFromContent(const vector<uint8_t>& content, uint16_t&
     }
     else {
       // XXX FIXME THIS MIGHT BE VERY SLOW!
-      ret.reserve(ret.size() + labellen + 2);
+
       for(string::size_type n = 0 ; n < labellen; ++n, frompos++) {
         if(content.at(frompos)=='.' || content.at(frompos)=='\\') {
           ret.append(1, '\\');