Bug#28317 Left Outer Join with {oj outer-join}

Parser rejects ODBC's escape sequences for outer joins other
than left outer join, yet the escape sequence BNF specifies
that this syntax can be used for left, right, and full outer
join syntax.

The problem is that although the MySQL Connector/ODBC advertises
"Outer Join Escape Sequence" capabilities, the parsing is done
in the server and historically it only supported this syntax
for left outer joins and applications such as Crystal Reports
11 tries to use this syntax for inner joins.

The chosen solution is to reorganize a couple of parser rules
to ignore any kind of SQL escape sequence. Ignoring the escape
sequences is harmless because the various SQL join clauses
are supported by the server.


mysql-test/r/parser.result:
  Add test case result for Bug#28317
mysql-test/t/parser.test:
  Add test case for Bug#28317
sql/sql_yacc.yy:
  Reorganize rules in order to ignore SQL Escape Sequences

1 files changed, 17 insertions, 24 deletions

diff --git a/sql/sql_yacc.yy b/sql/sql_yacc.yy
index 80e354aef98..c2f99f75c92 100644
--- a/sql/sql_yacc.yy
+++ b/sql/sql_yacc.yy
@@ -508,10 +508,10 @@ bool my_yyoverflow(short **a, YYSTYPE **b, ulong *yystacksize);
 
 %pure_parser                                    /* We have threads */
 /*
-  Currently there are 177 shift/reduce conflicts.
+  Currently there are 169 shift/reduce conflicts.
   We should not introduce new conflicts any more.
 */
-%expect 177
+%expect 169
 
 /*
    Comments for TOKENS.
@@ -1193,7 +1193,7 @@ bool my_yyoverflow(short **a, YYSTYPE **b, ulong *yystacksize);
 
 %type <table_list>
         join_table_list  join_table
-        table_factor table_ref
+        table_factor table_ref esc_table_ref
         select_derived derived_table_list
 
 %type <date_time_type> date_time_type;
@@ -7444,10 +7444,22 @@ join_table_list:
           derived_table_list { MYSQL_YYABORT_UNLESS($$=$1); }
         ;
 
+/*
+  The ODBC escape syntax for Outer Join is: '{' OJ join_table '}'
+  The parser does not define OJ as a token, any ident is accepted
+  instead in $2 (ident). Also, all productions from table_ref can
+  be escaped, not only join_table. Both syntax extensions are safe
+  and are ignored.
+*/
+esc_table_ref:
+        table_ref { $$=$1; }
+      | '{' ident table_ref '}' { $$=$3; }
+      ;
+
 /* Warning - may return NULL in case of incomplete SELECT */
 derived_table_list:
-          table_ref { $$=$1; }
-        | derived_table_list ',' table_ref
+          esc_table_ref { $$=$1; }
+        | derived_table_list ',' esc_table_ref
           {
             MYSQL_YYABORT_UNLESS($1 && ($$=$3));
           }
@@ -7612,25 +7624,6 @@ table_factor:
               MYSQL_YYABORT;
             Select->add_joined_table($$);
           }
-        | '{' ident table_ref LEFT OUTER JOIN_SYM table_ref
-          ON
-          {
-            /* Change the current name resolution context to a local context. */
-            if (push_new_name_resolution_context(YYTHD, $3, $7))
-              MYSQL_YYABORT;
-
-          }
-          expr '}'
-          {
-            LEX *lex= Lex;
-            MYSQL_YYABORT_UNLESS($3 && $7);
-            add_join_on($7,$10);
-            Lex->pop_context();
-            $7->outer_join|=JOIN_TYPE_LEFT;
-            $$=$7;
-            if (!($$= lex->current_select->nest_last_join(lex->thd)))
-              MYSQL_YYABORT;
-          }
         | select_derived_init get_select_lex select_derived2
           {
             LEX *lex= Lex;