diff --git a/src/evalfunc.c b/src/evalfunc.c
index 20c5f89..c30b57b 100644
--- a/src/evalfunc.c
+++ b/src/evalfunc.c
@@ -390,7 +390,7 @@
 static void f_tempname(typval_T *argvars, typval_T *rettv);
 static void f_test_alloc_fail(typval_T *argvars, typval_T *rettv);
 static void f_test_autochdir(typval_T *argvars, typval_T *rettv);
-static void f_test_disable_char_avail(typval_T *argvars, typval_T *rettv);
+static void f_test_override(typval_T *argvars, typval_T *rettv);
 static void f_test_garbagecollect_now(typval_T *argvars, typval_T *rettv);
 static void f_test_ignore_error(typval_T *argvars, typval_T *rettv);
 #ifdef FEAT_JOB_CHANNEL
@@ -828,7 +828,6 @@
     {"tempname",	0, 0, f_tempname},
     {"test_alloc_fail",	3, 3, f_test_alloc_fail},
     {"test_autochdir",	0, 0, f_test_autochdir},
-    {"test_disable_char_avail", 1, 1, f_test_disable_char_avail},
     {"test_garbagecollect_now",	0, 0, f_test_garbagecollect_now},
     {"test_ignore_error",	1, 1, f_test_ignore_error},
 #ifdef FEAT_JOB_CHANNEL
@@ -841,6 +840,7 @@
     {"test_null_list",	0, 0, f_test_null_list},
     {"test_null_partial", 0, 0, f_test_null_partial},
     {"test_null_string", 0, 0, f_test_null_string},
+    {"test_override",    2, 2, f_test_override},
     {"test_settime",	1, 1, f_test_settime},
 #ifdef FEAT_TIMERS
     {"timer_info",	0, 1, f_timer_info},
@@ -12326,12 +12326,34 @@
 }
 
 /*
- * "test_disable_char_avail({expr})" function
+ * "test_disable({name}, {val})" function
  */
     static void
-f_test_disable_char_avail(typval_T *argvars, typval_T *rettv UNUSED)
+f_test_override(typval_T *argvars, typval_T *rettv UNUSED)
 {
-    disable_char_avail_for_testing = (int)get_tv_number(&argvars[0]);
+    char_u *name = (char_u *)"";
+    int     val;
+
+    if (argvars[0].v_type != VAR_STRING
+	    || (argvars[1].v_type) != VAR_NUMBER)
+	EMSG(_(e_invarg));
+    else
+    {
+	name = get_tv_string_chk(&argvars[0]);
+	val = (int)get_tv_number(&argvars[1]);
+
+	if (STRCMP(name, (char_u *)"redraw") == 0)
+	    disable_redraw_for_testing = val;
+	else if (STRCMP(name, (char_u *)"char_avail") == 0)
+	    disable_char_avail_for_testing = val;
+	else if (STRCMP(name, (char_u *)"ALL") == 0)
+	{
+	    disable_char_avail_for_testing = FALSE;
+	    disable_redraw_for_testing = FALSE;
+	}
+	else
+	    EMSG2(_(e_invarg2), name);
+    }
 }
 
 /*