1 files changed, 72 insertions, 16 deletions

diff --git a/sql/sql_yacc.yy b/sql/sql_yacc.yy
index 08972afbf9a..53dd524ac65 100644
--- a/sql/sql_yacc.yy
+++ b/sql/sql_yacc.yy
@@ -780,6 +780,7 @@ static bool add_create_index (LEX *lex, Key::Keytype type,
   Diag_condition_item_name diag_condition_item_name;
   DYNCALL_CREATE_DEF *dyncol_def;
   List<DYNCALL_CREATE_DEF> *dyncol_def_list;
+  bool is_not_empty;
 }
 
 %{
@@ -1675,6 +1676,9 @@ END_OF_INPUT
         '-' '+' '*' '/' '%' '(' ')'
         ',' '!' '{' '}' '&' '|' AND_SYM OR_SYM OR_OR_SYM BETWEEN_SYM CASE_SYM
         THEN_SYM WHEN_SYM DIV_SYM MOD_SYM OR2_SYM AND_AND_SYM DELETE_SYM
+
+%type <is_not_empty> opt_union_order_or_limit
+
 %%
 
 /*
@@ -9387,6 +9391,7 @@ sum_expr:
             if ($$ == NULL)
               MYSQL_YYABORT;
             $5->empty();
+            sel->gorder_list.empty();
           }
         ;
 
@@ -9456,18 +9461,27 @@ opt_gconcat_separator:
 
 opt_gorder_clause:
           /* empty */
+        | ORDER_SYM BY
           {
-            Select->gorder_list = NULL;
-          }
-        | order_clause
-          {
-            SELECT_LEX *select= Select;
-            select->gorder_list= new (YYTHD->mem_root)
-                                   SQL_I_List<ORDER>(select->order_list);
-            if (select->gorder_list == NULL)
+            LEX *lex= Lex;
+            SELECT_LEX *sel= lex->current_select;
+            if (sel->linkage != GLOBAL_OPTIONS_TYPE &&
+                sel->olap != UNSPECIFIED_OLAP_TYPE &&
+                (sel->linkage != UNION_TYPE || sel->braces))
+            {
+              my_error(ER_WRONG_USAGE, MYF(0),
+                       "CUBE/ROLLUP", "ORDER BY");
               MYSQL_YYABORT;
-            select->order_list.empty();
+            }
           }
+         gorder_list;
+        ;
+
+gorder_list:
+          gorder_list ',' order_ident order_dir
+          { if (add_gorder_to_list(YYTHD, $3,(bool) $4)) MYSQL_YYABORT; }
+        | order_ident order_dir
+          { if (add_gorder_to_list(YYTHD, $1,(bool) $2)) MYSQL_YYABORT; }
         ;
 
 in_sum_expr:
@@ -9874,12 +9888,16 @@ table_factor:
               lex->pop_context();
               lex->nest_level--;
             }
-            else if (($3->select_lex &&
+            /*else if (($3->select_lex &&
                       $3->select_lex->master_unit()->is_union() &&
                       ($3->select_lex->master_unit()->first_select() ==
-                       $3->select_lex || !$3->lifted)) || $5)
+                       $3->select_lex || !$3->lifted)) || $5)*/
+            else if ($5 != NULL)
             {
-              /* simple nested joins cannot have aliases or unions */
+              /*
+                Tables with or without joins within parentheses cannot
+                have aliases, and we ruled out derived tables above.
+              */
               my_parse_error(ER(ER_SYNTAX_ERROR));
               MYSQL_YYABORT;
             }
@@ -9892,8 +9910,34 @@ table_factor:
           }
         ;
 
+/*
+  This rule accepts just about anything. The reason is that we have
+  empty-producing rules in the beginning of rules, in this case
+  subselect_start. This forces bison to take a decision which rules to
+  reduce by long before it has seen any tokens. This approach ties us
+  to a very limited class of parseable languages, and unfortunately
+  SQL is not one of them. The chosen 'solution' was this rule, which
+  produces just about anything, even complete bogus statements, for
+  instance ( table UNION SELECT 1 ).
+  Fortunately, we know that the semantic value returned by
+  select_derived is NULL if it contained a derived table, and a pointer to
+  the base table's TABLE_LIST if it was a base table. So in the rule
+  regarding union's, we throw a parse error manually and pretend it
+  was bison that did it.
+ 
+  Also worth noting is that this rule concerns query expressions in
+  the from clause only. Top level select statements and other types of
+  subqueries have their own union rules.
+*/
 select_derived_union:
           select_derived opt_union_order_or_limit
+          {
+            if ($1 && $2)
+            {
+              my_parse_error(ER(ER_SYNTAX_ERROR));
+              MYSQL_YYABORT;
+            }
+          }
         | select_derived_union
           UNION_SYM
           union_option
@@ -9910,6 +9954,13 @@ select_derived_union:
             Lex->pop_context();
           }
           opt_union_order_or_limit
+          {
+            if ($1 != NULL)
+            {
+              my_parse_error(ER(ER_SYNTAX_ERROR));
+              MYSQL_YYABORT;
+            }
+          }
         ;
 
 /* The equivalent of select_init2 for nested queries. */
@@ -11374,7 +11425,9 @@ show:
             bzero((char*) &lex->create_info,sizeof(lex->create_info));
           }
           show_param
-          {}
+          {
+            Select->parsing_place= NO_MATTER;
+          }
         ;
 
 show_param:
@@ -11752,7 +11805,10 @@ describe:
             if (prepare_schema_table(YYTHD, lex, $2, SCH_COLUMNS))
               MYSQL_YYABORT;
           }
-          opt_describe_column {}
+          opt_describe_column
+          {
+            Select->parsing_place= NO_MATTER;
+          }
         | describe_command opt_extended_describe
           { Lex->describe|= DESCRIBE_NORMAL; }
           select
@@ -14505,8 +14561,8 @@ union_opt:
         ;
 
 opt_union_order_or_limit:
-	  /* Empty */
-	| union_order_or_limit
+          /* Empty */{ $$= false; }
+	| union_order_or_limit { $$= true; }
 	;
 
 union_order_or_limit: