diff --git a/client/mysqltest.c b/client/mysqltest.c
index 1b02218ede3..639021cd889 100644
--- a/client/mysqltest.c
+++ b/client/mysqltest.c
@@ -1342,7 +1342,7 @@ int diff_check()
 {
  char buf[512]= {0};
  FILE *res_file;
- char *cmd = "diff -v";
+ const char *cmd = "diff -v";
  int have_diff = 0;
 
   if (!(res_file= popen(cmd, "r")))
diff --git a/mysql-test/r/mysql.result b/mysql-test/r/mysql.result
index 65f163a7acc..25b66fe7fc6 100644
--- a/mysql-test/r/mysql.result
+++ b/mysql-test/r/mysql.result
@@ -186,6 +186,8 @@ delimiter
 2
 2
 2
+@z:='1'	@z=database()
+1	NULL
 End of 5.0 tests
 WARNING: --server-arg option not supported in this configuration.
 Warning (Code 1286): Unknown table engine 'nonexistent'
diff --git a/mysql-test/t/mysql.test b/mysql-test/t/mysql.test
index f17613a68a5..a182da5fbea 100644
--- a/mysql-test/t/mysql.test
+++ b/mysql-test/t/mysql.test
@@ -310,6 +310,11 @@ EOF
 --exec $MYSQL -c < $MYSQLTEST_VARDIR/tmp/bug38158.sql 2>&1
 remove_file $MYSQLTEST_VARDIR/tmp/bug38158.sql;
 
+#
+# Bug #41437: Value stored in 'case' lacks charset, causees segfault
+#
+--exec $MYSQL -e "select @z:='1',@z=database()"
+
 --echo End of 5.0 tests
 
 #
diff --git a/sql/item_strfunc.cc b/sql/item_strfunc.cc
index bb3f4821c4f..fc9375e68a5 100644
--- a/sql/item_strfunc.cc
+++ b/sql/item_strfunc.cc
@@ -1782,6 +1782,12 @@ Item *Item_func_sysconst::safe_charset_converter(CHARSET_INFO *tocs)
   Item_string *conv;
   uint conv_errors;
   String tmp, cstr, *ostr= val_str(&tmp);
+  if (null_value)
+  {
+    Item *null_item= new Item_null((char *) fully_qualified_func_name());
+    null_item->collation.set (tocs);
+    return null_item;
+  }
   cstr.copy(ostr->ptr(), ostr->length(), ostr->charset(), tocs, &conv_errors);
   if (conv_errors ||
       !(conv= new Item_static_string_func(fully_qualified_func_name(),
diff --git a/sql/sql_partition.cc b/sql/sql_partition.cc
index ad24aa3c283..ae55c194c3c 100644
--- a/sql/sql_partition.cc
+++ b/sql/sql_partition.cc
@@ -6678,6 +6678,7 @@ int get_part_iter_for_interval_via_mapping(partition_info *part_info,
   uint32             max_endpoint_val;
   get_endpoint_func  get_endpoint;
   uint field_len= field->pack_length_in_rec();
+  part_iter->ret_null_part= part_iter->ret_null_part_orig= FALSE;
 
   if (part_info->part_type == RANGE_PARTITION)
   {
@@ -6698,7 +6699,6 @@ int get_part_iter_for_interval_via_mapping(partition_info *part_info,
     max_endpoint_val=    part_info->no_list_values;
     part_iter->get_next= get_next_partition_id_list;
     part_iter->part_info= part_info;
-    part_iter->ret_null_part= part_iter->ret_null_part_orig= FALSE;
     if (max_endpoint_val == 0)
     {
       /*