Bug#15463: EXPLAIN SELECT..INTO hangs the client (QB, command line)

There were two distict bugs: parse error was returned for valid
statement and that error wasn't reported to the client.

The fix ensures that EXPLAIN SELECT..INTO is accepted by parser and any
other parse error will be reported to the client.

1 files changed, 15 insertions, 5 deletions

diff --git a/sql/sql_yacc.yy b/sql/sql_yacc.yy
index 6473163a6ec..261d10f3e79 100644
--- a/sql/sql_yacc.yy
+++ b/sql/sql_yacc.yy
@@ -5795,7 +5795,11 @@ select_var_ident:
 	     if (lex->result) 
 	       ((select_dumpvar *)lex->result)->var_list.push_back( new my_var($2,0,0,(enum_field_types)0));
 	     else
-	       YYABORT;
+               /*
+                 The parser won't create select_result instance only
+	         if it's an EXPLAIN.
+               */
+               DBUG_ASSERT(lex->describe);
 	   }
            | ident_or_text
            {
@@ -5807,10 +5811,8 @@ select_var_ident:
 	       my_error(ER_SP_UNDECLARED_VAR, MYF(0), $1.str);
 	       YYABORT;
 	     }
-	     if (! lex->result)
-	       YYABORT;
-	     else
-	     {
+	     if (lex->result)
+             {
                my_var *var;
 	       ((select_dumpvar *)lex->result)->
                  var_list.push_back(var= new my_var($1,1,t->offset,t->type));
@@ -5818,6 +5820,14 @@ select_var_ident:
 	       if (var)
 		 var->sp= lex->sphead;
 #endif
+             }
+	     else
+	     {
+               /*
+                 The parser won't create select_result instance only
+	         if it's an EXPLAIN.
+               */
+               DBUG_ASSERT(lex->describe);
 	     }
 	   }
            ;