SQL: parsing of QUERY FOR [fixes #159]

Reverts 46e36bbffa7cd8d9eb861a22755025ffe8751449 - SQL: fix assertion failure in parser

mysql-test/suite/versioning/r/select.result

@@ -426,9 +426,19 @@ a	a
 2	3
 3	3
 1	NULL
+create or replace table t1 (x int) with system versioning;
+create or replace table t2 (y int) with system versioning;
+insert into t1 values (1), (2), (3);
+delete from t1 where x = 3;
+insert into t2 values (1);
+select * from t1, t2 query for system_time all;
+x	y
+1	1
+2	1
+3	1
 drop view v1;
 drop table t1, t2;
-call innodb_verify_vtq(24);
+call innodb_verify_vtq(27);
 No	A	B	C	D
 1	1	1	1	1
 2	1	1	1	1
@@ -454,6 +464,9 @@ No	A	B	C	D
 22	1	1	1	1
 23	1	1	1	1
 24	1	1	1	1
+25	1	1	1	1
+26	1	1	1	1
+27	1	1	1	1
 drop procedure test_01;
 drop procedure test_02;
 drop procedure verify_vtq;

mysql-test/suite/versioning/t/select.test

@@ -190,10 +190,17 @@ insert into t1 values (2);
 insert into t1 values (3);
 select * from t1 left outer join (t1 as t2 left join t1 as t3 using (a)) on t1.a>1;
 
+create or replace table t1 (x int) with system versioning;
+create or replace table t2 (y int) with system versioning;
+insert into t1 values (1), (2), (3);
+delete from t1 where x = 3;
+insert into t2 values (1);
+select * from t1, t2 query for system_time all;
+
 drop view v1;
 drop table t1, t2;
 
-call innodb_verify_vtq(24);
+call innodb_verify_vtq(27);
 
 drop procedure test_01;
 drop procedure test_02;

sql/sql_lex.cc

@@ -1368,6 +1368,21 @@ int MYSQLlex(YYSTYPE *yylval, THD *thd)
       return FOR_SYM;
     }
     break;
+  case QUERY_SYM:
+  {
+    CHARSET_INFO *cs= thd->charset();
+    const char *p= lip->get_ptr();
+    while (my_isspace(cs, *p))
+      ++p;
+    if (lip->get_end_of_query() - p > 3 && my_isspace(cs, p[3]) &&
+        0 == strncasecmp(p, "for", 3))
+    {
+      token= lex_one_token(yylval, thd);
+      lip->add_digest_token(token, yylval);
+      return QUERY_FOR_SYM;
+    }
+    return QUERY_SYM;
+  }
   default:
     break;
   }

sql/sql_yacc.yy

@@ -861,10 +861,10 @@ bool my_yyoverflow(short **a, YYSTYPE **b, ulong *yystacksize);
 %parse-param { THD *thd }
 %lex-param { THD *thd }
 /*
-  Currently there are 106 shift/reduce conflicts.
+  Currently there are 103 shift/reduce conflicts.
   We should not introduce new conflicts any more.
 */
-%expect 106
+%expect 103
 
 /*
    Comments for TOKENS.
@@ -1353,6 +1353,7 @@ bool my_yyoverflow(short **a, YYSTYPE **b, ulong *yystacksize);
 %token  PURGE
 %token  QUARTER_SYM
 %token  QUERY_SYM
+%token  QUERY_FOR_SYM                 /* INTERNAL */
 %token  QUICK
 %token  RAISE_SYM                     /* Oracle-PLSQL-R */
 %token  RANGE_SYM                     /* SQL-2003-R */
@@ -8828,7 +8829,7 @@ trans_or_timestamp:
 opt_query_for_system_time_clause:
           /* empty */
           {}
-        | QUERY_SYM FOR_SYSTEM_TIME_SYM for_system_time_expr
+        | QUERY_FOR_SYM SYSTEM_TIME_SYM for_system_time_expr
           {
             DBUG_ASSERT(Select);
             Select->vers_conditions= Lex->vers_conditions;
@@ -11705,21 +11706,15 @@ date_time_type:
         | TIMESTAMP {$$=MYSQL_TIMESTAMP_DATETIME;}
         ;
 
+table_alias:
+          /* empty */
+        | AS
+        | '='
+        ;
+
 opt_table_alias:
           /* empty */ { $$=0; }
-        | ident
-          {
-            $$= (LEX_STRING*) thd->memdup(&$1,sizeof(LEX_STRING));
-            if ($$ == NULL)
-              MYSQL_YYABORT;
-          }
-        | AS ident
-          {
-            $$= (LEX_STRING*) thd->memdup(&$2,sizeof(LEX_STRING));
-            if ($$ == NULL)
-              MYSQL_YYABORT;
-          }
-        | '=' ident
+        | table_alias ident
           {
             $$= (LEX_STRING*) thd->memdup(&$2,sizeof(LEX_STRING));
             if ($$ == NULL)