Fixing that 3.23 API / clients do not disconnect if a large

packet is issued.

libmysql/libmysql.c

@@ -456,6 +456,14 @@ simple_command(MYSQL *mysql,enum enum_server_command command, const char *arg,
 			length ? length : (ulong) strlen(arg)))
   {
     DBUG_PRINT("error",("Can't send command to server. Error: %d",socket_errno));
+    if (net->last_errno == ER_NET_PACKET_TOO_LARGE)
+    {
+      net->last_errno=CR_NET_PACKET_TOO_LARGE;
+      strmov(net->last_error,ER(net->last_errno));
+      return(packet_error);
+    }
+    else
+    {
       end_server(mysql);
       if (mysql_reconnect(mysql) ||
 	  net_write_command(net,(uchar) command,arg,
@@ -466,6 +474,7 @@ simple_command(MYSQL *mysql,enum enum_server_command command, const char *arg,
 	goto end;
       }
     }
+  }
   result=0;
   if (!skipp_check)
     result= ((mysql->packet_length=net_safe_read(mysql)) == packet_error ?

sql/net_serv.cc

@@ -34,13 +34,18 @@
 #include <signal.h>
 #include <errno.h>
 #include <sys/types.h>
+#ifdef MYSQL_SERVER
+#include <violite.h>
+#endif
+
+#define MAX_PACKET_LENGTH (256L*256L*256L-1)
 
 #ifdef MYSQL_SERVER
 ulong max_allowed_packet=65536;
 extern ulong net_read_timeout,net_write_timeout;
 extern uint test_flags;
 #else
-ulong max_allowed_packet=16*1024*1024L-1;
+ulong max_allowed_packet=MAX_PACKET_LENGTH;
 ulong net_read_timeout=  NET_READ_TIMEOUT;
 ulong net_write_timeout= NET_WRITE_TIMEOUT;
 #endif
@@ -226,6 +231,12 @@ int
 my_net_write(NET *net,const char *packet,ulong len)
 {
   uchar buff[NET_HEADER_SIZE];
+  if (len >= MAX_PACKET_LENGTH)
+  {
+    net->error=1;
+    net->last_errno=ER_NET_PACKET_TOO_LARGE;
+    return 1;
+  }
   int3store(buff,len);
   buff[3]= (net->compress) ? 0 : (uchar) (net->pkt_nr++);
   if (net_write_buff(net,(char*) buff,NET_HEADER_SIZE))
@@ -238,7 +249,12 @@ net_write_command(NET *net,uchar command,const char *packet,ulong len)
 {
   uchar buff[NET_HEADER_SIZE+1];
   uint length=len+1;				/* 1 extra byte for command */
-
+  if (length >= MAX_PACKET_LENGTH)
+  {
+    net->error=1;
+    net->last_errno=ER_NET_PACKET_TOO_LARGE;
+    return 1;
+  }
   int3store(buff,length);
   buff[3]= (net->compress) ? 0 : (uchar) (net->pkt_nr++);
   buff[4]=command;
@@ -276,7 +292,7 @@ net_real_write(NET *net,const char *packet,ulong len)
   int length;
   char *pos,*end;
   thr_alarm_t alarmed;
-#if !defined(__WIN__)
+#if !defined(__WIN__) && !defined(__EMX__) && !defined(OS2)
   ALARM alarm_buff;
 #endif
   uint retry_count=0;

sql/sql_select.cc

@@ -2328,8 +2328,7 @@ make_join_select(JOIN *join,SQL_SELECT *select,COND *cond)
 
 	  if ((tab->keys & ~ tab->const_keys && i > 0) ||
 	      tab->const_keys && i == join->const_tables &&
-	      join->thd->select_limit < join->best_positions[i].records_read &&
-	      join->tables > 1)
+	      join->thd->select_limit < join->best_positions[i].records_read)
 	  {
 	    /* Join with outer join condition */
 	    COND *orig_cond=sel->cond;