diff --git a/src/cmdexpand.c b/src/cmdexpand.c
index 71c4f69..9e88d99 100644
--- a/src/cmdexpand.c
+++ b/src/cmdexpand.c
@@ -2900,6 +2900,7 @@
 		|| check_for_opt_bool_arg(argvars, 2) == FAIL))
 	return;
 
+    pat = tv_get_string(&argvars[0]);
     if (argvars[1].v_type != VAR_STRING)
     {
 	semsg(_(e_invarg2), "type must be a string");
@@ -2920,12 +2921,13 @@
     ExpandInit(&xpc);
     if (STRCMP(type, "cmdline") == 0)
     {
-	set_one_cmd_context(&xpc, tv_get_string(&argvars[0]));
+	set_one_cmd_context(&xpc, pat);
 	xpc.xp_pattern_len = (int)STRLEN(xpc.xp_pattern);
+	xpc.xp_col = (int)STRLEN(pat);
     }
     else
     {
-	xpc.xp_pattern = tv_get_string(&argvars[0]);
+	xpc.xp_pattern = pat;
 	xpc.xp_pattern_len = (int)STRLEN(xpc.xp_pattern);
 
 	xpc.xp_context = cmdcomplete_str_to_type(type);
diff --git a/src/testdir/test_cmdline.vim b/src/testdir/test_cmdline.vim
index 295e59d..abd1246 100644
--- a/src/testdir/test_cmdline.vim
+++ b/src/testdir/test_cmdline.vim
@@ -424,14 +424,17 @@
   call assert_equal([], l)
 
   func T(a, c, p)
+    let g:cmdline_compl_params = [a:a, a:c, a:p]
     return "oneA\noneB\noneC"
   endfunc
   command -nargs=1 -complete=custom,T MyCmd
   let l = getcompletion('MyCmd ', 'cmdline')
   call assert_equal(['oneA', 'oneB', 'oneC'], l)
+  call assert_equal(['', 'MyCmd ', 6], g:cmdline_compl_params)
 
   delcommand MyCmd
   delfunc T
+  unlet g:cmdline_compl_params
 
   " For others test if the name is recognized.
   let names = ['buffer', 'environment', 'file_in_path', 'mapping', 'tag', 'tag_listfiles', 'user']
diff --git a/src/version.c b/src/version.c
index f508d77..76cc5a4 100644
--- a/src/version.c
+++ b/src/version.c
@@ -758,6 +758,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    3638,
+/**/
     3637,
 /**/
     3636,