BUG#12537203 - CRASH WHEN SUBSELECTING GLOBAL VARIABLES IN GEOMETRY FUNCTION ARGUMENTS

A defect in the subquery substitution code may lead to a server crash:
setting substitution's name should be followed by setting its length
(to keep them in sync).

mysql-test/r/gis.result

@@ -1081,4 +1081,10 @@ DROP TABLE t0, t1, t2;
 SELECT ISCLOSED(CONVERT(CONCAT('     ', 0x2), BINARY(20)));
 ISCLOSED(CONVERT(CONCAT('     ', 0x2), BINARY(20)))
 NULL
+#
+# BUG#12537203 - CRASH WHEN SUBSELECTING GLOBAL VARIABLES IN 
+# GEOMETRY FUNCTION ARGUMENTS
+#
+SELECT GEOMETRYCOLLECTION((SELECT @@OLD));
+ERROR 22007: Illegal non geometric '' value found during parsing
 End of 5.1 tests

mysql-test/t/gis.test

@@ -818,5 +818,12 @@ DROP TABLE t0, t1, t2;
 --echo #
 SELECT ISCLOSED(CONVERT(CONCAT('     ', 0x2), BINARY(20)));
 
+--echo #
+--echo # BUG#12537203 - CRASH WHEN SUBSELECTING GLOBAL VARIABLES IN 
+--echo # GEOMETRY FUNCTION ARGUMENTS
+--echo #
+--error ER_ILLEGAL_VALUE_FOR_TYPE
+SELECT GEOMETRYCOLLECTION((SELECT @@OLD));
+
 
 --echo End of 5.1 tests

sql/item_subselect.cc

@@ -173,6 +173,7 @@ bool Item_subselect::fix_fields(THD *thd_param, Item **ref)
 
       (*ref)= substitution;
       substitution->name= name;
+      substitution->name_length= name_length;
       if (have_to_be_excluded)
 	engine->exclude();
       substitution= 0;