From 96f0aa3cfbb58810516e7f07505153f303bbcad8 Mon Sep 17 00:00:00 2001
From: "kroki@mysql.com" <>
Date: Wed, 3 May 2006 18:02:43 +0400
Subject: [PATCH] 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.
---
 mysql-test/r/explain.result |  4 ++++
 mysql-test/t/explain.test   |  9 +++++++++
 sql/sql_parse.cc            |  1 +
 sql/sql_yacc.yy             | 20 +++++++++++++++-----
 4 files changed, 29 insertions(+), 5 deletions(-)

diff --git a/mysql-test/r/explain.result b/mysql-test/r/explain.result
index d66dec741bd..75e1548cdee 100644
--- a/mysql-test/r/explain.result
+++ b/mysql-test/r/explain.result
@@ -53,3 +53,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	таб	ref	инд0,инд01	инд0	5	const	1	Using where; Using index
 drop table таб;
 set names latin1;
+select 3 into @v1;
+explain select 3 into @v1;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
diff --git a/mysql-test/t/explain.test b/mysql-test/t/explain.test
index 2a3a23c5f96..a38771db233 100644
--- a/mysql-test/t/explain.test
+++ b/mysql-test/t/explain.test
@@ -43,3 +43,12 @@ drop table 
 set names latin1;
 
 # End of 4.1 tests
+
+
+#
+# Bug#15463: EXPLAIN SELECT..INTO hangs the client (QB, command line)
+#
+select 3 into @v1;
+explain select 3 into @v1;
+
+# End of 5.0 tests.
diff --git a/sql/sql_parse.cc b/sql/sql_parse.cc
index 196e723299a..649714315a6 100644
--- a/sql/sql_parse.cc
+++ b/sql/sql_parse.cc
@@ -5709,6 +5709,7 @@ void mysql_parse(THD *thd, char *inBuf, uint length)
     }
     else
     {
+      DBUG_ASSERT(thd->net.report_error);
       DBUG_PRINT("info",("Command aborted. Fatal_error: %d",
 			 thd->is_fatal_error));
       query_cache_abort(&thd->net);
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);
 	     }
 	   }
            ;