patch 8.2.1732: stuck when win_execute() for a popup causes an error

Problem:    Stuck when win_execute() for a popup causes an error.
Solution:   Disable the filter callback on error. (issue #6999)

src/testdir/term_util.vim

@@ -5,6 +5,8 @@ if exists('*CanRunVimInTerminal')
   finish
 endif
 
+source shared.vim
+
 " For most tests we need to be able to run terminal Vim with 256 colors.  On
 " MS-Windows the console only has 16 colors and the GUI can't run in a
 " terminal.
@@ -51,6 +53,7 @@ endfunc
 " "rows" - height of the terminal window (max. 20)
 " "cols" - width of the terminal window (max. 78)
 " "statusoff" - number of lines the status is offset from default
+" "wait_for_ruler" - if zero then don't wait for ruler to show
 func RunVimInTerminal(arguments, options)
   " If Vim doesn't exit a swap file remains, causing other tests to fail.
   " Remove it here.