diff --git a/mysql-test/r/variables.result b/mysql-test/r/variables.result
index 4983e0ae3e8..a5b76c03b29 100644
--- a/mysql-test/r/variables.result
+++ b/mysql-test/r/variables.result
@@ -513,6 +513,11 @@ SHOW VARIABLES LIKE 'table_cache';
 Variable_name	Value
 table_cache	1
 SET GLOBAL table_cache=DEFAULT;
+set character_set_results=NULL;
+select ifnull(@@character_set_results,"really null");
+ifnull(@@character_set_results,"really null")
+really null
+set names latin1;
 create table t1 (a int);
 select a into @x from t1;
 Warnings:
diff --git a/mysql-test/t/variables.test b/mysql-test/t/variables.test
index 7ce2cf22db0..372e865467e 100644
--- a/mysql-test/t/variables.test
+++ b/mysql-test/t/variables.test
@@ -390,6 +390,14 @@ SET GLOBAL table_cache=-1;
 SHOW VARIABLES LIKE 'table_cache';
 SET GLOBAL table_cache=DEFAULT;
 
+#
+# Bugs12363: character_set_results is nullable,
+# but value_ptr returns string "NULL"
+#
+set character_set_results=NULL;
+select ifnull(@@character_set_results,"really null");
+set names latin1;
+
 # End of 4.1 tests
 
 #
diff --git a/scripts/mysqld_multi.sh b/scripts/mysqld_multi.sh
index 642772bca44..098cd894916 100644
--- a/scripts/mysqld_multi.sh
+++ b/scripts/mysqld_multi.sh
@@ -412,7 +412,12 @@ sub get_mysqladmin_options
   $mysqladmin_found= 0 if (!length($mysqladmin));
   $com = "$mysqladmin";
   $tmp = " -u $opt_user";
-  $tmp.= defined($opt_password) ? " -p$opt_password" : "";
+  if (defined($opt_password)) {
+    my $pw= $opt_password;
+    # Protect single quotes in password
+    $pw =~ s/'/'"'"'/g;
+    $tmp.= " -p'$pw'";
+  }
   $tmp.= $opt_tcp_ip ? " -h 127.0.0.1" : "";
   for ($j = 0; defined($options[$j]); $j++)
   {
diff --git a/sql/set_var.cc b/sql/set_var.cc
index 26912becc81..ea4c08cea27 100644
--- a/sql/set_var.cc
+++ b/sql/set_var.cc
@@ -1725,11 +1725,17 @@ Item *sys_var::item(THD *thd, enum_var_type var_type, LEX_STRING *base)
     return new Item_int((int32) *(my_bool*) value_ptr(thd, var_type, base),1);
   case SHOW_CHAR:
   {
-    Item_string *tmp;
+    Item *tmp;
     pthread_mutex_lock(&LOCK_global_system_variables);
     char *str= (char*) value_ptr(thd, var_type, base);
-    tmp= new Item_string(str, strlen(str),
-                         system_charset_info, DERIVATION_SYSCONST);
+    if (str)
+      tmp= new Item_string(str, strlen(str),
+                           system_charset_info, DERIVATION_SYSCONST);
+    else
+    {
+      tmp= new Item_null();
+      tmp->collation.set(system_charset_info, DERIVATION_SYSCONST);
+    }
     pthread_mutex_unlock(&LOCK_global_system_variables);
     return tmp;
   }
@@ -2019,7 +2025,7 @@ byte *sys_var_character_set::value_ptr(THD *thd, enum_var_type type,
 				       LEX_STRING *base)
 {
   CHARSET_INFO *cs= ci_ptr(thd,type)[0];
-  return cs ? (byte*) cs->csname : (byte*) "NULL";
+  return cs ? (byte*) cs->csname : (byte*) NULL;
 }