Bug#44367 valgrind warnings with find_in_set() functions

init 'wc' variable

mysql-test/r/func_set.result

@@ -103,3 +103,46 @@ CAST(DATE(NULL) AS DECIMAL), CAST(DATE(NULL) AS DECIMAL),
 CAST(DATE(NULL) AS DECIMAL), CAST(DATE(NULL) AS DECIMAL))
 8
 End of 5.0 tests
+drop table if exists t1;
+create table t1 (f1 set('test1','test2','test3') character set utf8 default null)
+engine=myisam default charset=latin1;
+insert into t1 values (''),(null),(null),(''),(''),('');
+select find_in_set(f1,f1) as a from t1,(select find_in_set(f1,f1) as b from t1) a;
+a
+0
+NULL
+NULL
+0
+0
+0
+0
+NULL
+NULL
+0
+0
+0
+0
+NULL
+NULL
+0
+0
+0
+0
+NULL
+NULL
+0
+0
+0
+0
+NULL
+NULL
+0
+0
+0
+0
+NULL
+NULL
+0
+0
+0
+drop table t1;

mysql-test/t/func_set.test

@@ -72,3 +72,15 @@ SELECT INTERVAL(0.0, CAST(DATE(NULL) AS DECIMAL), CAST(DATE(NULL) AS DECIMAL),
   CAST(DATE(NULL) AS DECIMAL), CAST(DATE(NULL) AS DECIMAL));
 
 --echo End of 5.0 tests
+
+#
+# Bug#44367 valgrind warnings with find_in_set() functions
+#
+--disable_warnings
+drop table if exists t1;
+--enable_warnings
+create table t1 (f1 set('test1','test2','test3') character set utf8 default null)
+engine=myisam default charset=latin1;
+insert into t1 values (''),(null),(null),(''),(''),('');
+select find_in_set(f1,f1) as a from t1,(select find_in_set(f1,f1) as b from t1) a;
+drop table t1;

sql/item_func.cc

@@ -2716,7 +2716,7 @@ longlong Item_func_find_in_set::val_int()
   int diff;
   if ((diff=buffer->length() - find->length()) >= 0)
   {
-    my_wc_t wc;
+    my_wc_t wc= 0;
     CHARSET_INFO *cs= cmp_collation.collation;
     const char *str_begin= buffer->ptr();
     const char *str_end= buffer->ptr();