fixed couple of bugs in field/reference name resolution

fixed error handling in subselect fix_field


mysql-test/r/subselect.result:
  test of name resolution
mysql-test/t/subselect.test:
  test of name resolution
sql/item.cc:
  fixed couple of bugs in field/reference name resolution.
sql/item_subselect.cc:
  fixed error handling
sql/mysql_priv.h:
  fixed couple of bugs in field/reference name resolution.
sql/sql_base.cc:
  fixed couple of bugs in field/reference name resolution.
sql/sql_select.cc:
  new find_item_in_list interface

mysql-test/r/subselect.result

@@ -131,6 +131,8 @@ patient_uq	clinic_uq
 1	1
 1	2
 2	2
+select * from t1 where a= (select a from t2,t4 where t2.b=t4.b);
+Column: 'a' in field list is ambiguous
 drop table if exists t1,t2,t3;
 CREATE TABLE t3 (a varchar(20),b char(1) NOT NULL default '0');
 INSERT INTO t3 VALUES ('W','a'),('A','c'),('J','b');
@@ -159,4 +161,4 @@ INSERT INTO inscrit (pseudo,email) VALUES ('joce1','test1');
 INSERT INTO inscrit (pseudo,email) VALUES ('2joce1','2test1');
 SELECT pseudo FROM inscrit WHERE pseudo=(SELECT pseudo FROM inscrit WHERE pseudo LIKE '%joce%');
 Subselect returns more than 1 record
-drop table if exists inscrit;
+drop table if exists t1,t2,t3,t4,t5,attend,clinic,inscrit;

mysql-test/t/subselect.test

@@ -53,6 +53,10 @@ insert into clinic values(1,"Oblastnaia bolnitsa"),(2,"Bolnitsa Krasnogo Kresta"
 insert into attend values (1,1),(1,2),(2,2),(1,3);
 select * from attend where exists (select * from clinic where uq = clinic_uq);
 
+# not unique fields
+-- error 1052
+select * from t1 where a= (select a from t2,t4 where t2.b=t4.b);
+
 # different tipes & group functions
 drop table if exists t1,t2,t3;
 
@@ -81,4 +85,4 @@ INSERT INTO inscrit (pseudo,email) VALUES ('2joce1','2test1');
 -- error 1240
 SELECT pseudo FROM inscrit WHERE pseudo=(SELECT pseudo FROM inscrit WHERE pseudo LIKE '%joce%');
 
-drop table if exists inscrit;
\ No newline at end of file
+drop table if exists t1,t2,t3,t4,t5,attend,clinic,inscrit;
\ No newline at end of file

sql/item.cc

@@ -432,7 +432,7 @@ bool Item_field::fix_fields(THD *thd, TABLE_LIST *tables, Item **ref)
   if (!field)					// If field is not checked
   {
     Field *tmp;
-    if (!(tmp=find_field_in_tables(thd, this, tables, 0)))
+    if ((tmp= find_field_in_tables(thd, this, tables, 0)) == not_found_field)
     {
       /*
 	We can't find table field in table list of current select, 
@@ -445,14 +445,18 @@ bool Item_field::fix_fields(THD *thd, TABLE_LIST *tables, Item **ref)
       */
       SELECT_LEX *last= 0;
       for (SELECT_LEX *sl= thd->lex.select->outer_select();
-	   sl && !tmp;
+	   sl;
 	   sl= sl->outer_select())
-	tmp=find_field_in_tables(thd, this,
-				 (TABLE_LIST*)(last= sl)->table_list.first,
-				 0);
+	if ((tmp= find_field_in_tables(thd, this,
+				       (TABLE_LIST*)
+				       (last= sl)->table_list.first,
+				       0)) != not_found_field)
+	  break;
       if (!tmp)
+	return -1;
+      else if (tmp == not_found_field)
       {
-	// Call to produce appropriate error message
+	// call to return error code
 	find_field_in_tables(thd, this, tables, 1);
 	return -1;
       }
@@ -479,6 +483,9 @@ bool Item_field::fix_fields(THD *thd, TABLE_LIST *tables, Item **ref)
 	  }
       }
     } 
+    else if (!tmp)
+      return -1;
+
     set_field(tmp);
   }
   else if (thd && thd->set_query_id && field->query_id != thd->query_id)
@@ -786,7 +793,9 @@ bool Item_ref::fix_fields(THD *thd,TABLE_LIST *tables, Item **reference)
 {
   if (!ref)
   {
-        if (!(ref= find_item_in_list(this, thd->lex.select->item_list, 0)))
+    if ((ref= find_item_in_list(this, thd->lex.select->item_list,
+				REPORT_EXCEPT_NOT_FOUND)) ==
+	not_found_item)
     {
       /*
 	We can't find table field in table list of current select, 
@@ -795,17 +804,25 @@ bool Item_ref::fix_fields(THD *thd,TABLE_LIST *tables, Item **reference)
 	of view rules. For example if both tables (outer & current) have 
 	field 'field' it is not mistake to refer to this field without 
 	mention of table name, but if we join tables in one list it will
-	cause error ER_NON_UNIQ_ERROR in find_field_in_tables.
+	cause error ER_NON_UNIQ_ERROR in find_item_in_list.
       */
       SELECT_LEX *last=0;
       for (SELECT_LEX *sl= thd->lex.select->outer_select();
-	   sl && !ref;
+	   sl;
 	   sl= sl->outer_select())
-	ref= find_item_in_list(this, (last= sl)->item_list, 0);
+	if((ref= find_item_in_list(this, (last= sl)->item_list,
+				   REPORT_EXCEPT_NOT_FOUND)) !=
+	   not_found_item)
+	  break;
+
       if (!ref)
+      {
+	return 1;
+      }
+      else if (ref == not_found_item)
       {
 	// Call to report error
-	find_item_in_list(this, thd->lex.select->item_list, 1);
+	find_item_in_list(this, thd->lex.select->item_list, REPORT_ALL_ERRORS);
 	return 1;
       }
       else
@@ -831,6 +848,8 @@ bool Item_ref::fix_fields(THD *thd,TABLE_LIST *tables, Item **reference)
 	  }
       }
     }
+    else if (!ref)
+      return 1;
     max_length= (*ref)->max_length;
     maybe_null= (*ref)->maybe_null;
     decimals=	(*ref)->decimals;

sql/item_subselect.cc

@@ -83,6 +83,7 @@ bool Item_subselect::fix_fields(THD *thd, TABLE_LIST *tables, Item **ref)
     return 1;
   }
   int res= engine->prepare();
+  if (!res)
     fix_length_and_dec();
   return res;
 }

sql/mysql_priv.h

@@ -456,6 +456,7 @@ bool wait_for_tables(THD *thd);
 bool table_is_used(TABLE *table, bool wait_for_name_lock);
 bool drop_locked_tables(THD *thd,const char *db, const char *table_name);
 void abort_locked_tables(THD *thd,const char *db, const char *table_name);
+extern const Field *not_found_field;
 Field *find_field_in_tables(THD *thd, Item_field *item, TABLE_LIST *tables,
 			    bool report_error);
 Field *find_field_in_table(THD *thd,TABLE *table,const char *name,uint length,
@@ -545,7 +546,11 @@ TABLE *unlink_open_table(THD *thd,TABLE *list,TABLE *find);
 
 SQL_SELECT *make_select(TABLE *head, table_map const_tables,
 			table_map read_tables, COND *conds, int *error);
-Item ** find_item_in_list(Item *item, List<Item> &items, bool report_error);
+enum find_item_error_report_type {REPORT_ALL_ERRORS, REPORT_EXCEPT_NOT_FOUND,
+				  IGNORE_ERRORS};
+extern const Item **not_found_item;
+Item ** find_item_in_list(Item *item, List<Item> &items, 
+			  find_item_error_report_type report_error);
 bool insert_fields(THD *thd,TABLE_LIST *tables, 
 		   const char *db_name, const char *table_name,
 		   List_iterator<Item> *it);

sql/sql_base.cc

@@ -1781,9 +1781,29 @@ Field *find_field_in_table(THD *thd,TABLE *table,const char *name,uint length,
   return field;
 }
 
+// Special Field pointer for find_field_in_tables returning
+const Field *not_found_field= (Field*) 0x1;
+/*
+  Find field in table list.
+
+  SYNOPSIS
+    find_field_in_tables()
+    thd - pointer to current thread structure
+    item - field item that should be found
+    tables - tables for scaning
+    report_error - if FALSE then do not report error if item not found and 
+      return not_found_field;
+
+  RETURN VALUES
+    0 - field is not found or field is not unique, error message is 
+      reported
+    not_found_field - function was called with report_error == FALSE and 
+      field if not found, no error message reported
+    found field
+*/
 
 Field *
-find_field_in_tables(THD *thd,Item_field *item,TABLE_LIST *tables,
+find_field_in_tables(THD *thd, Item_field *item, TABLE_LIST *tables,
 		     bool report_error)
 {
   Field *found=0;
@@ -1829,13 +1849,18 @@ find_field_in_tables(THD *thd,Item_field *item,TABLE_LIST *tables,
 	strxnmov(buff,sizeof(buff)-1,db,".",table_name,NullS);
 	table_name=buff;
       }
-      my_printf_error(ER_UNKNOWN_TABLE,ER(ER_UNKNOWN_TABLE),MYF(0),table_name,
-		      thd->where);
+      if (report_error)
+	my_printf_error(ER_UNKNOWN_TABLE, ER(ER_UNKNOWN_TABLE), MYF(0),
+			table_name, thd->where);
+      else
+	return (Field*) not_found_field;
     }
     else
       if (report_error)
 	my_printf_error(ER_BAD_FIELD_ERROR,ER(ER_BAD_FIELD_ERROR),MYF(0),
 			item->full_name(),thd->where);
+      else
+	return (Field*) not_found_field;
     return (Field*) 0;
   }
   bool allow_rowid= tables && !tables->next;	// Only one table
@@ -1850,9 +1875,8 @@ find_field_in_tables(THD *thd,Item_field *item,TABLE_LIST *tables,
 	return (Field*) 0;
       if (found)
       {
-	if (!report_error)			// Returns first found
+	if (!thd->where)			// Returns first found
 	  break;
-	if (report_error)
 	my_printf_error(ER_NON_UNIQ_ERROR,ER(ER_NON_UNIQ_ERROR),MYF(0),
 			name,thd->where);
 	return (Field*) 0;
@@ -1865,11 +1889,39 @@ find_field_in_tables(THD *thd,Item_field *item,TABLE_LIST *tables,
   if (report_error)
     my_printf_error(ER_BAD_FIELD_ERROR, ER(ER_BAD_FIELD_ERROR),
 		    MYF(0), item->full_name(), thd->where);
+  else
+    return (Field*) not_found_field;
   return (Field*) 0;
 }
 
+// Special Item pointer for find_item_in_list returning
+const Item **not_found_item= (const Item**) 0x1;
+
+/*
+  Find Item in list of items (find_field_in_tables analog)
+  
+  SYNOPSIS
+    find_item_in_list()
+    find - item to find
+    items - list of items
+    report_error
+      REPORT_ALL_ERRORS - report errors, return 0 if error
+      REPORT_EXCEPT_NOT_FOUND - do not report 'not found' error and return not_        found_item, report other errors, return 0
+      IGNORE_ERRORS - do not report errors, return 0 if error
+      
+  RETURN VALUES
+    0 - item is not found or item is not unique, error message is 
+      reported
+    not_found_item - function was called with report_error ==  
+      REPORT_EXCEPT_NOT_FOUND and  item if not found, no error 
+      message reported
+    found field 
+  
+*/
+
 Item **
-find_item_in_list(Item *find, List<Item> &items, bool report_error)
+find_item_in_list(Item *find, List<Item> &items,
+		  find_item_error_report_type report_error)
 {
   List_iterator<Item> li(items);
   Item **found=0,*item;
@@ -1894,7 +1946,7 @@ find_item_in_list(Item *find, List<Item> &items, bool report_error)
 	  {
 	    if ((*found)->eq(item,0))
 	      continue;				// Same field twice (Access?)
-	    if (report_error)
+	    if (report_error != IGNORE_ERRORS)
 	      my_printf_error(ER_NON_UNIQ_ERROR,ER(ER_NON_UNIQ_ERROR),MYF(0),
 			      find->full_name(), current_thd->where);
 	    return (Item**) 0;
@@ -1917,10 +1969,17 @@ find_item_in_list(Item *find, List<Item> &items, bool report_error)
       break;
     }
   }
-  if (!found && report_error)
+  if (found)
+    return found;
+  else if (report_error != REPORT_EXCEPT_NOT_FOUND)
+  {
+    if (report_error == REPORT_ALL_ERRORS)
       my_printf_error(ER_BAD_FIELD_ERROR, ER(ER_BAD_FIELD_ERROR), MYF(0),
 		      find->full_name(), current_thd->where);
-  return found;
+    return (Item **) 0;
+  }
+  else
+    return (Item **) not_found_item;
 }
 
 /****************************************************************************

sql/sql_select.cc

@@ -6487,7 +6487,7 @@ find_order_in_list(THD *thd,TABLE_LIST *tables,ORDER *order,List<Item> &fields,
     order->in_field_list=1;
     return 0;
   }
-  Item **item=find_item_in_list(*order->item, fields, 0);
+  Item **item= find_item_in_list(*order->item, fields, IGNORE_ERRORS);
   if (item)
   {
     order->item=item;				// use it
@@ -6587,7 +6587,7 @@ setup_new_fields(THD *thd,TABLE_LIST *tables,List<Item> &fields,
   thd->set_query_id=1;				// Not really needed, but...
   for (; new_field ; new_field= new_field->next)
   {
-    if ((item= find_item_in_list(*new_field->item, fields, 0)))
+    if ((item= find_item_in_list(*new_field->item, fields, IGNORE_ERRORS)))
       new_field->item=item;			/* Change to shared Item */
     else
     {