patch 8.2.4328: command line complete matches cleard when typing character

Problem:    Command line complete matches cleard when typing character.
            (Dominique Pellé)
Solution:   Only remove a popup menu if there is one.

src/ex_getln.c

@@ -1883,6 +1883,7 @@ getcmdline_int(
 		&& c != Ctrl_L)
 	{
 #ifdef FEAT_WILDMENU
+	    if (cmdline_pum_active())
 		cmdline_pum_remove();
 #endif
 	    (void)ExpandOne(&xpc, NULL, NULL, 0, WILD_FREE);

src/testdir/dumps/Test_wildmenu_pum_30.dump

@@ -0,0 +1,10 @@
+|~+0#4040ff13#ffffff0| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|:+0#0000000&|c|n| @71
+|c|n|e|w|e|r| @6|c|n|f|i|l|e| @6|c|n|o|r|e|m|a|p| @40
+|c|n|e|x|t| @7|c|n|o|r|e|a|b@1|r|e|v| @1|c|n|o|r|e|m|e|n|u| @39
+|:|c|n> @71

src/testdir/dumps/Test_wildmenu_pum_31.dump

@@ -0,0 +1,10 @@
+|~+0#4040ff13#ffffff0| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|:+0#0000000&|c|n| @71
+|c|n|e|w|e|r| @6|c|n|f|i|l|e| @6|c|n|o|r|e|m|a|p| @40
+|c|n|e|x|t| @7|c|n|o|r|e|a|b@1|r|e|v| @1|c|n|o|r|e|m|e|n|u| @39
+|:|c|n|s> @70

src/testdir/test_cmdline.vim

@@ -2132,6 +2132,15 @@ func Test_wildmenu_pum()
   call TermWait(buf)
   call VerifyScreenDump(buf, 'Test_wildmenu_pum_29', {})
 
+  " Check "list" still works
+  call term_sendkeys(buf, "\<C-U>set wildmode=longest,list\<CR>")
+  call term_sendkeys(buf, ":cn\<Tab>")
+  call TermWait(buf)
+  call VerifyScreenDump(buf, 'Test_wildmenu_pum_30', {})
+  call term_sendkeys(buf, "s")
+  call TermWait(buf)
+  call VerifyScreenDump(buf, 'Test_wildmenu_pum_31', {})
+
   call term_sendkeys(buf, "\<C-U>\<CR>")
   call StopVimInTerminal(buf)
   call delete('Xtest')

src/version.c

@@ -746,6 +746,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    4328,
 /**/
     4327,
 /**/