patch 8.2.5094: MS-Windows GUI: empty command may cause a dialog

Problem:    MS-Windows GUI: empty command may cause a dialog.
Solution:   Delete the dialog file.  Improve the message.

src/testdir/runtest.vim

@@ -246,8 +246,7 @@ func RunTheTest(test)
   endif
 
   if filereadable('guidialogfile')
-    call add(v:errors, "Unexpected dialog:")
+    call add(v:errors, "Unexpected dialog: " .. readfile('guidialogfile')->join('<NL>'))
-    call add(v:errors, readfile('guidialogfile').join('\n'))
     call delete('guidialogfile')
   endif
 

src/testdir/test_ex_mode.vim

@@ -261,6 +261,9 @@ func Test_empty_command_visual_mode()
   call assert_equal(1, RunVim([], [], '-u NONE -e -s -S Xexmodescript'))
 
   call delete('Xexmodescript')
+
+  " This may cause a dialog to be displayed for an empty command, ignore it.
+  call delete('guidialogfile')
 endfunc
 
 

src/version.c

@@ -734,6 +734,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    5094,
 /**/
     5093,
 /**/