Fix for #2208 (multi-query returns wrong result in embedded library)

now we execute only one first select during mysql_real_query
others - during 'mysql_next_result'


include/mysql.h:
  'virtual' next_result added
libmysql/client_settings.h:
  cli_next_result declaration added
libmysql/libmysql.c:
  mysql_next_result now works in embedded library as well
libmysqld/lib_sql.cc:
  emb_next_result implemented
sql/sql_class.h:
  fields to store the rest of the query added
sql/sql_parse.cc:
  Saving the rest of the query added for embedded case

include/mysql.h

@@ -575,6 +575,7 @@ typedef struct st_mysql_methods
   int (*unbuffered_fetch)(MYSQL *mysql, char **row);
   void (*free_embedded_thd)(MYSQL *mysql);
   const char *(*read_statistic)(MYSQL *mysql);
+  int (*next_result)(MYSQL *mysql);
 #endif
 } MYSQL_METHODS;
 

libmysql/client_settings.h

@@ -58,6 +58,7 @@ int cli_stmt_execute(MYSQL_STMT *stmt);
 MYSQL_DATA * cli_read_binary_rows(MYSQL_STMT *stmt);
 int cli_unbuffered_fetch(MYSQL *mysql, char **row);
 const char * cli_read_statistic(MYSQL *mysql);
+int cli_next_result(MYSQL *mysql);
 
 #ifdef EMBEDDED_LIBRARY
 int init_embedded_server(int argc, char **argv, char **groups);

libmysql/libmysql.c

@@ -3511,6 +3511,21 @@ my_bool STDCALL mysql_more_results(MYSQL *mysql)
   Reads and returns the next query results
 */
 
+int cli_next_result(MYSQL *mysql)
+{
+  DBUG_ENTER("cli_next_result");
+
+  mysql->net.last_error[0]= 0;
+  mysql->net.last_errno= 0;
+  strmov(mysql->net.sqlstate, not_error_sqlstate);
+  mysql->affected_rows= ~(my_ulonglong) 0;
+
+  if (mysql->last_used_con->server_status & SERVER_MORE_RESULTS_EXISTS)
+    DBUG_RETURN((*mysql->methods->read_query_result)(mysql));
+  
+  DBUG_RETURN(-1);				/* No more results */
+}
+
 int STDCALL mysql_next_result(MYSQL *mysql)
 {
   DBUG_ENTER("mysql_next_result");
@@ -3523,15 +3538,7 @@ int STDCALL mysql_next_result(MYSQL *mysql)
     DBUG_RETURN(1);
   }
 
-  mysql->net.last_error[0]= 0;
-  mysql->net.last_errno= 0;
-  strmov(mysql->net.sqlstate, not_error_sqlstate);
-  mysql->affected_rows= ~(my_ulonglong) 0;
-
-  if (mysql->last_used_con->server_status & SERVER_MORE_RESULTS_EXISTS)
-    DBUG_RETURN((*mysql->methods->read_query_result)(mysql));
-  
-  DBUG_RETURN(-1);				/* No more results */
+  DBUG_RETURN((*mysql->methods->next_result)(mysql));
 }
 
 

libmysqld/lib_sql.cc

@@ -245,6 +245,18 @@ static MYSQL_RES * emb_mysql_store_result(MYSQL *mysql)
   return mysql_store_result(mysql);
 }
 
+int emb_next_result(MYSQL *mysql)
+{
+  THD *thd= (THD*)mysql->thd;
+  DBUG_ENTER("emb_next_result");
+
+  if (emb_advanced_command(mysql, COM_QUERY,0,0,
+			   thd->query_rest,thd->query_rest_length,1)
+      || emb_mysql_read_query_result(mysql))
+    DBUG_RETURN(1);
+
+  DBUG_RETURN(0);				/* No more results */
+}
 
 MYSQL_METHODS embedded_methods= 
 {
@@ -259,7 +271,8 @@ MYSQL_METHODS embedded_methods=
   emb_read_binary_rows,
   emb_unbuffered_fetch,
   emb_free_embedded_thd,
-  emb_read_statistic
+  emb_read_statistic,
+  emb_next_result
 };
 
 C_MODE_END
@@ -749,6 +762,11 @@ bool Protocol::net_store_data(const char *from, uint length)
   return false;
 }
 
+char *memdup_mysql(struct st_mysql *mysql, const char*data, int length)
+{
+  return memdup_root(&mysql->field_alloc, data, length);
+}
+
 #if 0
 /* The same as Protocol::net_store_data but does the converstion
 */

sql/sql_class.h

@@ -565,6 +565,8 @@ public:
   struct st_mysql_bind *client_params;
   char *extra_data;
   ulong extra_length;
+  char *query_rest;
+  uint32 query_rest_length;
 #endif
   NET	  net;				// client connection descriptor
   MEM_ROOT warn_root;			// For warnings and errors

sql/sql_parse.cc

@@ -48,6 +48,7 @@
 extern "C" int gethostname(char *name, int namelen);
 #endif
 
+char *memdup_mysql(struct st_mysql *mysql, const char*data, int length);
 static int check_for_max_user_connections(THD *thd, USER_CONN *uc);
 static void decrease_user_connections(USER_CONN *uc);
 static bool check_db_used(THD *thd,TABLE_LIST *tables);
@@ -1397,11 +1398,13 @@ bool dispatch_command(enum enum_server_command command, THD *thd,
       char *packet= thd->lex->found_colon;
       /*
         Multiple queries exits, execute them individually
+	in embedded server - just store them to be executed later 
       */
+#ifndef EMBEDDED_LIBRARY
       if (thd->lock || thd->open_tables || thd->derived_tables)
         close_thread_tables(thd);
-
-      ulong length= thd->query_length-(ulong)(thd->lex->found_colon-thd->query);
+#endif
+      ulong length= thd->query_length-(ulong)(packet-thd->query);
 
       /* Remove garbage at start of query */
       while (my_isspace(thd->charset(), *packet) && length > 0)
@@ -1414,7 +1417,13 @@ bool dispatch_command(enum enum_server_command command, THD *thd,
       VOID(pthread_mutex_lock(&LOCK_thread_count));
       thd->query_id= query_id++;
       VOID(pthread_mutex_unlock(&LOCK_thread_count));
+#ifndef EMBEDDED_LIBRARY
       mysql_parse(thd, packet, length);
+#else
+      thd->query_rest= (char*)memdup_mysql(thd->mysql, packet, length);
+      thd->query_rest_length= length;
+      break;
+#endif /*EMBEDDED_LIBRARY*/
     }
 
     if (!(specialflag & SPECIAL_NO_PRIOR))