bk commit into 5.0 tree (acurtis:1.1808) BUG#8670

[antony]

Below is the list of changes that have just been committed into a local
5.0 repository of acurtis. When acurtis does a push these changes will
be propagated to the main repository and, within 24 hours after the
push, to the public repository.
For information on how to access the public repository
see http://dev.mysql.com/doc/mysql/en/installing-source-tree.html

ChangeSet
  1.1808 05/03/16 00:13:23 acurtis@stripped +4 -0
  Bug#8670
    Rework to resolve ambigious grammer: conflict in join expression
    handling of parentheses for nested joins and derived tables.
    Tests included of failing statements
  Optimize item construction for AND/OR logical expressions

  sql/sql_yacc.yy
    1.349 05/03/16 00:12:59 acurtis@stripped +183 -49
    Optimize construction for Item_cond_or and Item_cond_and
      Reduces object count in case of complex expressions.
    Bug#8670
      Solve ambigious grammar.
      Fix handling of parentheses in join expressions to
      correct handling of nested joins and derived tables.

  sql/sql_parse.cc
    1.416 05/03/16 00:12:59 acurtis@stripped +7 -0
    Bug#8670
      method st_select_lex::end_nested_join() returns NULL when
      there are no elements in the join.

  mysql-test/t/select.test
    1.41 05/03/16 00:12:58 acurtis@stripped +10 -0
    Bug#8670
      Tests for failing expressions

  mysql-test/r/select.result
    1.54 05/03/16 00:12:58 acurtis@stripped +9 -0
    Bug#8670
      Tests for failing expressions

# This is a BitKeeper patch.  What follows are the unified diffs for the
# set of deltas contained in the patch.  The rest of the patch, the part
# that BitKeeper cares about, is below these diffs.
# User:	acurtis
# Host:	pcgem.rdg.cyberkinetica.com
# Root:	/var/db/bk/work-acurtis/bug8670.2

--- 1.415/sql/sql_parse.cc	2005-03-09 07:25:09 +00:00
+++ 1.416/sql/sql_parse.cc	2005-03-16 00:12:59 +00:00
@@ -5852,6 +5852,7 @@
 {
   TABLE_LIST *ptr;
   DBUG_ENTER("end_nested_join");
+  DBUG_ASSERT(embedding);
   ptr= embedding;
   join_list= ptr->join_list;
   embedding= ptr->embedding;
@@ -5864,6 +5865,12 @@
     embedded->embedding= embedding;
     join_list->push_front(embedded);
     ptr= embedded;
+  }
+  else
+  if (nested_join->join_list.elements == 0)
+  {
+    join_list->pop();
+    DBUG_RETURN(0);
   }
   DBUG_RETURN(ptr);
 }

--- 1.348/sql/sql_yacc.yy	2005-03-08 18:53:03 +00:00
+++ 1.349/sql/sql_yacc.yy	2005-03-16 00:12:59 +00:00
@@ -52,6 +52,13 @@
 		      ER_WARN_DEPRECATED_SYNTAX, \
 		      ER(ER_WARN_DEPRECATED_SYNTAX), (A), (B));
 
+#define TEST_ASSERT(A) \
+  if (!(A)) \
+  {					\
+    yyerror(ER(ER_SYNTAX_ERROR));	\
+    YYABORT;				\
+  }
+
 /* Helper for parsing "IS [NOT] truth_value" */
 inline Item *is_truth_value(Item *A, bool v1, bool v2)
 {
@@ -692,6 +699,7 @@
         opt_var_ident_type delete_option opt_temporary all_or_any opt_distinct
         opt_ignore_leaves fulltext_options spatial_type union_option
         start_transaction_opts opt_chain opt_release
+        union_opt select_derived_init
 
 %type <ulong_num>
 	ULONG_NUM raid_types merge_insert_types
@@ -737,6 +745,7 @@
 %type <table_list>
 	join_table_list  join_table
         table_factor table_ref
+        select_derived derived_table_list
 
 %type <date_time_type> date_time_type;
 %type <interval> interval
@@ -771,6 +780,7 @@
 %type <variable> internal_variable_name
 
 %type <select_lex> in_subselect in_subselect_init
+	get_select_lex
 
 %type <boolfunc2creator> comp_op
 
@@ -4022,13 +4032,53 @@
 
 /* all possible expressions */
 expr:	
-	expr or bool_term	{ $$= new Item_cond_or($1,$3); }
-	| expr XOR bool_term	{ $$= new Item_cond_xor($1,$3); }
-	| bool_term ;
+	  bool_term { Select->expr_list.push_front(new List<Item>); }
+          bool_or_expr
+          {
+            List<Item> *list= Select->expr_list.pop();
+            if (list->elements)
+            {
+              list->push_front($1);
+              $$= new Item_cond_or(*list);
+              /* optimize construction of logical OR to reduce
+                 amount of objects for complex expressions */
+            }
+            else
+              $$= $1;
+            delete list;
+          }
+	;
+
+bool_or_expr:
+	/* empty */
+        | bool_or_expr or bool_term
+          { Select->expr_list.head()->push_back($3); }
+        ;
 
 bool_term:
-	bool_term and bool_factor { $$= new Item_cond_and($1,$3); }
-	| bool_factor ;
+	bool_term XOR bool_term { $$= new Item_cond_xor($1,$3); }
+	| bool_factor { Select->expr_list.push_front(new List<Item>); }
+          bool_and_expr
+          {
+            List<Item> *list= Select->expr_list.pop();
+            if (list->elements)
+            {
+              list->push_front($1);
+              $$= new Item_cond_and(*list);
+              /* optimize construction of logical AND to reduce
+                 amount of objects for complex expressions */
+            }
+            else
+              $$= $1;
+            delete list;
+          }
+	;
+
+bool_and_expr:
+	/* empty */
+        | bool_and_expr and bool_factor
+          { Select->expr_list.head()->push_back($3); }
+        ;
 
 bool_factor:
 	NOT_SYM bool_factor	{ $$= negate_expression(YYTHD, $2); }
@@ -4911,6 +4961,7 @@
 	    sel->when_list.head()->push_back($5);
 	  };
 
+/* Warning - may return NULL in case of incomplete SELECT */
 table_ref:
         table_factor            { $$=$1; }
         | join_table            { $$=$1; }
@@ -4922,36 +4973,47 @@
         ;
 
 join_table_list:
+	derived_table_list		{ TEST_ASSERT($$=$1); }
+	;
+        
+/* Warning - may return NULL in case of incomplete SELECT */
+derived_table_list:
         table_ref { $$=$1; }
-        | join_table_list ',' table_ref { $$=$3; }
+        | derived_table_list ',' table_ref
+          {
+            TEST_ASSERT($1 && ($$=$3));
+          }
         ;
 
 join_table:
-        table_ref normal_join table_ref { $$=$3; }
+        table_ref normal_join table_ref { TEST_ASSERT($1 && ($$=$3)); }
 	| table_ref STRAIGHT_JOIN table_factor
-	  { $3->straight=1; $$=$3 ; }
+	  {  TEST_ASSERT($1 && ($$=$3)); $3->straight=1; }
 	| table_ref normal_join table_ref ON expr
-	  { add_join_on($3,$5); $$=$3; }
+	  { TEST_ASSERT($1 && ($$=$3)); add_join_on($3,$5); }
 	| table_ref normal_join table_ref
 	  USING
 	  {
 	    SELECT_LEX *sel= Select;
+            TEST_ASSERT($1 && $3);
             sel->save_names_for_using_list($1, $3);
 	  }
 	  '(' using_list ')'
 	  { add_join_on($3,$7); $$=$3; }
 
 	| table_ref LEFT opt_outer JOIN_SYM table_ref ON expr
-	  { add_join_on($5,$7); $5->outer_join|=JOIN_TYPE_LEFT; $$=$5; }
+	  { TEST_ASSERT($1 && $5); add_join_on($5,$7);
$5->outer_join|=JOIN_TYPE_LEFT; $$=$5; }
 	| table_ref LEFT opt_outer JOIN_SYM table_factor
 	  {
 	    SELECT_LEX *sel= Select;
+            TEST_ASSERT($1 && $5);
             sel->save_names_for_using_list($1, $5);
 	  }
 	  USING '(' using_list ')'
 	  { add_join_on($5,$9); $5->outer_join|=JOIN_TYPE_LEFT; $$=$5; }
 	| table_ref NATURAL LEFT opt_outer JOIN_SYM table_factor
 	  {
+            TEST_ASSERT($1 && $6);
 	    add_join_natural($1,$6);
 	    $6->outer_join|=JOIN_TYPE_LEFT;
 	    $$=$6;
@@ -4959,6 +5021,7 @@
 	| table_ref RIGHT opt_outer JOIN_SYM table_ref ON expr
           { 
 	    LEX *lex= Lex;
+            TEST_ASSERT($1 && $5);
             if (!($$= lex->current_select->convert_right_join()))
               YYABORT;
             add_join_on($$, $7);
@@ -4966,6 +5029,7 @@
 	| table_ref RIGHT opt_outer JOIN_SYM table_factor
 	  {
 	    SELECT_LEX *sel= Select;
+            TEST_ASSERT($1 && $5);
             sel->save_names_for_using_list($1, $5);
 	  }
 	  USING '(' using_list ')'
@@ -4977,13 +5041,14 @@
           }
 	| table_ref NATURAL RIGHT opt_outer JOIN_SYM table_factor
 	  {
+            TEST_ASSERT($1 && $6);
 	    add_join_natural($6,$1);
 	    LEX *lex= Lex;
             if (!($$= lex->current_select->convert_right_join()))
               YYABORT;
 	  }
 	| table_ref NATURAL JOIN_SYM table_factor
-	  { add_join_natural($1,$4); $$=$4; };
+	  { TEST_ASSERT($1 && ($$=$4)); add_join_natural($1,$4); };
         
 
 normal_join:
@@ -4992,6 +5057,7 @@
 	| CROSS JOIN_SYM	{}
 	;
 
+/* Warning - may return NULL in case of incomplete SELECT */
 table_factor:
 	{
 	  SELECT_LEX *sel= Select;
@@ -5010,50 +5076,96 @@
 	    YYABORT;
           sel->add_joined_table($$);
 	}
-        | '('
+	| '{' ident table_ref LEFT OUTER JOIN_SYM table_ref ON expr '}'
+	  { TEST_ASSERT($3 && $7); add_join_on($7,$9);
$7->outer_join|=JOIN_TYPE_LEFT; $$=$7; }
+	| select_derived_init get_select_lex select_derived2
           {
             LEX *lex= Lex;
-            if (lex->current_select->init_nested_join(lex->thd))
-              YYABORT;
+            SELECT_LEX *sel= lex->current_select;
+            if ($1)
+            {
+	      if (sel->set_braces(1))
+	      {
+	        yyerror(ER(ER_SYNTAX_ERROR));
+	        YYABORT;
+	      }
+              /* select in braces, can't contain global parameters */
+	      if (sel->master_unit()->fake_select_lex)
+                sel->master_unit()->global_parameters=
+                   sel->master_unit()->fake_select_lex;
+            }
+            if ($2->init_nested_join(lex->thd))
+              YYABORT;            
+            $$= 0;
+            /* incomplete derived tables return NULL, we must be 
+               nested in select_derived rule to be here. */
+          }
+	| '(' get_select_lex select_derived union_opt ')' opt_table_alias
+	{
+          /* Use $2 instead of Lex->current_select as derived table will
+             alter value of Lex->current_select. */
+
+          if (!($3 || $6) && $2->embedding && 
+              !$2->embedding->nested_join->join_list.elements)
+          {
+            /* we have a derived table ($3 == NULL) but no alias,
+               Since we are nested in further parentheses so we
+               can pass NULL to the outer level parentheses
+               Permits parsing of "((((select ...))) as xyz)" */
+            $$= 0;
           }
-          join_table_list ')'
+          else
+          if (!$3)
           {
-            LEX *lex= Lex;
-            if (!($$= lex->current_select->end_nested_join(lex->thd)))
-              YYABORT;
-          }
-	| '{' ident table_ref LEFT OUTER JOIN_SYM table_ref ON expr '}'
-	  { add_join_on($7,$9); $7->outer_join|=JOIN_TYPE_LEFT; $$=$7; }
-	| '(' select_derived union_opt ')' opt_table_alias
-	{
-	  LEX *lex=Lex;
-	  SELECT_LEX_UNIT *unit= lex->current_select->master_unit();
-	  lex->current_select= unit->outer_select();
-	  if (!($$= lex->current_select->
-                add_table_to_list(lex->thd, new Table_ident(unit), $5, 0,
-				  TL_READ,(List<String> *)0,
-	                          (List<String> *)0)))
+            /* Handle case of derived table, alias may be NULL if there
+               are no outer parentheses, add_table_to_list() will throw
+               error in this case */
+	    LEX *lex=Lex;
+            SELECT_LEX *sel= lex->current_select;
+	    SELECT_LEX_UNIT *unit= sel->master_unit();
+	    lex->current_select= sel= unit->outer_select();
+	    if (!($$= sel->
+                  add_table_to_list(lex->thd, new Table_ident(unit), $6, 0,
+				    TL_READ,(List<String> *)0,
+	                            (List<String> *)0)))
 
+	      YYABORT;
+            sel->add_joined_table($$);           
+          }
+	  else
+          if ($4 || $6)
+	  {
+            /* simple nested joins cannot have aliases or unions */
+            yyerror(ER(ER_SYNTAX_ERROR));
 	    YYABORT;
-          lex->current_select->add_joined_table($$);           
-	};
-
+	  }
+          else
+            $$= $3;
+	}
+        ;
 
+/* handle contents of parentheses in join expression */
 select_derived:
-	SELECT_SYM select_derived2
-	| '(' select_derived ')'
+	  get_select_lex
 	  {
-            SELECT_LEX *sel= Select;
-	    if (sel->set_braces(1))
-	    {
+            LEX *lex= Lex;
+            if ($1->init_nested_join(lex->thd))
+              YYABORT;
+          }
+          derived_table_list
+          {
+            LEX *lex= Lex;
+            /* for normal joins, $3 != NULL and end_nested_join() != NULL,
+               for derived tables, both must equal NULL */
+            
+            if (!($$= $1->end_nested_join(lex->thd)) && $3)
+              YYABORT;
+            if (!$3 && $$)
+            {
 	      yyerror(ER(ER_SYNTAX_ERROR));
 	      YYABORT;
-	    }
-            /* select in braces, can't contain global parameters */
-	    if (sel->master_unit()->fake_select_lex)
-              sel->master_unit()->global_parameters=
-                 sel->master_unit()->fake_select_lex;
-	  }
+            }
+          }
  	;
 
 select_derived2:
@@ -5081,6 +5193,29 @@
 	opt_select_from
         ;
 
+get_select_lex:
+	/* Empty */ { $$= Select; }
+        ;
+
+select_derived_init:
+          SELECT_SYM
+          {
+            LEX *lex= Lex;
+            SELECT_LEX *sel= lex->current_select;        
+            TABLE_LIST *embedding;
+            if (!sel->embedding || sel->end_nested_join(lex->thd))
+	    {
+              /* we are not in parentheses */
+              yyerror(ER(ER_SYNTAX_ERROR));
+	      YYABORT;
+	    }
+            embedding= Select->embedding;
+            $$= embedding &&
+                !embedding->nested_join->join_list.elements;
+            /* return true if we are deeply nested */
+          }
+        ;
+
 opt_outer:
 	/* empty */	{}
 	| OUTER		{};
@@ -8077,13 +8212,12 @@
 	;
 
 union_opt:
-	union_list {}
-	| optional_order_or_limit {}
+	/* Empty */ { $$= 0; }
+	| union_list { $$= 1; }
+	| union_order_or_limit { $$= 1; }
 	;
 
-optional_order_or_limit:
-	/* Empty */ {}
-	|
+union_order_or_limit:
 	  {
 	    THD *thd= YYTHD;
 	    LEX *lex= thd->lex;

--- 1.53/mysql-test/r/select.result	2005-03-10 11:58:41 +00:00
+++ 1.54/mysql-test/r/select.result	2005-03-16 00:12:58 +00:00
@@ -2446,3 +2446,12 @@
 1
 18446744073709551615
 drop table t1;
+create table t1 (a int, b int);
+create table t2 like t1;
+select t1.a from (t1 inner join t2 on t1.a=t2.a) where t2.a=1;
+a
+select t1.a from ((t1 inner join t2 on t1.a=t2.a)) where t2.a=1;
+a
+select x.a, y.a, z.a from ( (t1 x inner join t2 y on x.a=y.a) inner join t2 z on y.a=z.a)
WHERE x.a=1;
+a	a	a
+drop table t1,t2;

--- 1.40/mysql-test/t/select.test	2005-03-10 11:58:41 +00:00
+++ 1.41/mysql-test/t/select.test	2005-03-16 00:12:58 +00:00
@@ -2015,3 +2015,13 @@
 select a-b as d, (a-b >= 0), b from t1 group by b having d >= 0;
 select cast((a - b) as unsigned) from t1 order by 1;
 drop table t1;
+
+#
+# Bug#8670
+#
+create table t1 (a int, b int);
+create table t2 like t1;
+select t1.a from (t1 inner join t2 on t1.a=t2.a) where t2.a=1;
+select t1.a from ((t1 inner join t2 on t1.a=t2.a)) where t2.a=1;
+select x.a, y.a, z.a from ( (t1 x inner join t2 y on x.a=y.a) inner join t2 z on y.a=z.a)
WHERE x.a=1;
+drop table t1,t2;