Fixes for bugs in embedded library:

#4700 (Unsigned value returned as signed)
    just no appropriate checking
#4701 (Errors returned earlier than expected)
    all errors returned from send_command()
#4702 (Result isn't freed properly if there's no retrieval)
    flush_use_result has only 'client' version and should
    be made 'virtual'


include/mysql.h:
  flush_use_result 'virtual' method added to MYSQL (#4701)
include/sql_common.h:
  no flush_use_result() now (#4702)
libmysql/libmysql.c:
  call of the flush_use_result changed (#4702)
libmysqld/lib_sql.cc:
  now errors returned from emb_advanced_command() or from emb_read_rows()
  depending on if number of returned fields is not 0 (#4701)
  emb_flush_use_result() implementation (#4702)
sql-common/client.c:
  cli_flush_use_result() implementation (#4702)
sql/sql_prepare.cc:
  unsigned flag now checked (#4700)

include/mysql.h

@@ -627,6 +627,7 @@ typedef struct st_mysql_methods
   MYSQL_RES * (*use_result)(MYSQL *mysql);
   void (*fetch_lengths)(unsigned long *to, 
 			MYSQL_ROW column, unsigned int field_count);
+  void (*flush_use_result)(MYSQL *mysql);
 #if !defined(MYSQL_SERVER) || defined(EMBEDDED_LIBRARY)
   MYSQL_FIELD * (*list_fields)(MYSQL *mysql);
   my_bool (*read_prepare_result)(MYSQL *mysql, MYSQL_STMT *stmt);

include/sql_common.h

@@ -25,7 +25,6 @@ extern "C" {
 MYSQL_FIELD *unpack_fields(MYSQL_DATA *data,MEM_ROOT *alloc,uint fields,
 			   my_bool default_value, uint server_capabilities);
 void free_rows(MYSQL_DATA *cur);
-void flush_use_result(MYSQL *mysql);
 my_bool mysql_autenticate(MYSQL *mysql, const char *passwd);
 void free_old_query(MYSQL *mysql);
 void end_server(MYSQL *mysql);

libmysql/libmysql.c

@@ -4181,7 +4181,7 @@ my_bool STDCALL mysql_stmt_free_result(MYSQL_STMT *stmt)
       if (mysql->status != MYSQL_STATUS_READY)
       {
         /* There is a result set and it belongs to this statement */
-        flush_use_result(mysql);
+        (*mysql->methods->flush_use_result)(mysql);
         mysql->status= MYSQL_STATUS_READY;
       }
     }
@@ -4231,7 +4231,7 @@ my_bool STDCALL mysql_stmt_close(MYSQL_STMT *stmt)
           Flush result set of the connection. If it does not belong
           to this statement, set a warning.
         */
-        flush_use_result(mysql);
+        (*mysql->methods->flush_use_result)(mysql);
         if (mysql->unbuffered_fetch_owner)
           *mysql->unbuffered_fetch_owner= TRUE;
         mysql->status= MYSQL_STATUS_READY;

libmysqld/lib_sql.cc

@@ -84,6 +84,7 @@ emb_advanced_command(MYSQL *mysql, enum enum_server_command command,
   thd->clear_error();
   mysql->affected_rows= ~(my_ulonglong) 0;
   mysql->field_count= 0;
+  net->last_errno= 0;
 
   thd->store_globals();				// Fix if more than one connect
   /* 
@@ -107,17 +108,32 @@ emb_advanced_command(MYSQL *mysql, enum enum_server_command command,
   if (!skip_check)
     result= thd->net.last_errno ? -1 : 0;
 
-  embedded_get_error(mysql);
+  if (!mysql->field_count)
+    embedded_get_error(mysql);
   mysql->server_status= thd->server_status;
   mysql->warning_count= ((THD*)mysql->thd)->total_warn_count;
   return result;
 }
 
+static void emb_flush_use_result(MYSQL *mysql)
+{
+  MYSQL_DATA *data= ((THD*)(mysql->thd))->data;
+
+  if (data)
+  {
+    free_rows(data);
+    ((THD*)(mysql->thd))->data= NULL;
+  }
+}
+
 static MYSQL_DATA *
 emb_read_rows(MYSQL *mysql, MYSQL_FIELD *mysql_fields __attribute__((unused)),
 	      unsigned int fields __attribute__((unused)))
 {
   MYSQL_DATA *result= ((THD*)mysql->thd)->data;
+  embedded_get_error(mysql);
+  if (mysql->net.last_errno)
+    return NULL;
   if (!result)
   {
     if (!(result=(MYSQL_DATA*) my_malloc(sizeof(MYSQL_DATA),
@@ -227,6 +243,9 @@ int emb_read_binary_rows(MYSQL_STMT *stmt)
 int emb_unbuffered_fetch(MYSQL *mysql, char **row)
 {
   MYSQL_DATA *data= ((THD*)mysql->thd)->data;
+  embedded_get_error(mysql);
+  if (mysql->net.last_errno)
+    return mysql->net.last_errno;
   if (!data || !data->data)
   {
     *row= NULL;
@@ -293,6 +312,7 @@ MYSQL_METHODS embedded_methods=
   emb_read_rows,
   emb_mysql_store_result,
   emb_fetch_lengths, 
+  emb_flush_use_result,
   emb_list_fields,
   emb_read_prepare_result,
   emb_stmt_execute,

sql-common/client.c

@@ -723,7 +723,7 @@ void set_mysql_error(MYSQL *mysql, int errcode, const char *sqlstate)
   Flush result set sent from server
 */
 
-void flush_use_result(MYSQL *mysql)
+static void cli_flush_use_result(MYSQL *mysql)
 {
   /* Clear the current execution status */
   DBUG_PRINT("warning",("Not all packets read, clearing them"));
@@ -842,7 +842,7 @@ mysql_free_result(MYSQL_RES *result)
         mysql->unbuffered_fetch_owner= 0;
       if (mysql->status == MYSQL_STATUS_USE_RESULT)
       {
-        flush_use_result(mysql);
+        (*mysql->methods->flush_use_result)(mysql);
         mysql->status=MYSQL_STATUS_READY;
       }
     }
@@ -1493,7 +1493,8 @@ static MYSQL_METHODS client_methods=
   cli_advanced_command,
   cli_read_rows,
   cli_use_result,
-  cli_fetch_lengths
+  cli_fetch_lengths,
+  cli_flush_use_result
 #ifndef MYSQL_SERVER
   ,cli_list_fields,
   cli_read_prepare_result,

sql/sql_prepare.cc

@@ -696,6 +696,7 @@ static bool emb_insert_params(Prepared_statement *stmt, String *expanded_query)
       else
       {
         uchar *buff= (uchar*) client_param->buffer;
+	param->unsigned_flag= client_param->is_unsigned;
         param->set_param_func(param, &buff,
                               client_param->length ? 
                               *client_param->length :