patch 8.1.1920: cannot always close a popup when filter consumes all events

Problem:    Cannot close a popup by the X when a filter consumes all events.
Solution:   Check for a click on the close button before invoking filters.
            (closes #4858)
diff --git a/src/testdir/dumps/Test_popupwin_close_04.dump b/src/testdir/dumps/Test_popupwin_close_04.dump
new file mode 100644
index 0000000..91d7f09
--- /dev/null
+++ b/src/testdir/dumps/Test_popupwin_close_04.dump
@@ -0,0 +1,10 @@
+>1+0&#ffffff0| @37|╔+0#0000001#ffd7ff255|═@5|X| +0#0000000#ffffff0@27
+|2| @37|║+0#0000001#ffd7ff255|b|a|r|f|o@1|║| +0#0000000#ffffff0@27
+|3| @37|╚+0#0000001#ffd7ff255|═@5|╝| +0#0000000#ffffff0@27
+|4| @73
+|5| |n+0#0000001#ffd7ff255|o| |b|o|r|d|e|r| |h|e|r|X| +0#0000000#ffffff0@5| +0#0000001#ffd7ff255@12|X| +0#0000000#ffffff0@38
+|6| @20| +0#0000001#ffd7ff255|o|n|l|y| |p|a|d@1|i|n|g| | +0#0000000#ffffff0@38
+|7| @20| +0#0000001#ffd7ff255@13| +0#0000000#ffffff0@38
+|8| @73
+|9| @73
+|:|c|a|l@1| |C|r|e|a|t|e|W|i|t|h|M|e|n|u|F|i|l|t|e|r|(|)| @28|1|,|1| @10|T|o|p| 
diff --git a/src/testdir/dumps/Test_popupwin_close_05.dump b/src/testdir/dumps/Test_popupwin_close_05.dump
new file mode 100644
index 0000000..75ce052
--- /dev/null
+++ b/src/testdir/dumps/Test_popupwin_close_05.dump
@@ -0,0 +1,10 @@
+>1+0&#ffffff0| @73
+|2| @73
+|3| @73
+|4| @73
+|5| |n+0#0000001#ffd7ff255|o| |b|o|r|d|e|r| |h|e|r|X| +0#0000000#ffffff0@5| +0#0000001#ffd7ff255@12|X| +0#0000000#ffffff0@38
+|6| @20| +0#0000001#ffd7ff255|o|n|l|y| |p|a|d@1|i|n|g| | +0#0000000#ffffff0@38
+|7| @20| +0#0000001#ffd7ff255@13| +0#0000000#ffffff0@38
+|8| @73
+|9| @73
+|:|c|a|l@1| |C|r|e|a|t|e|W|i|t|h|M|e|n|u|F|i|l|t|e|r|(|)| @28|1|,|1| @10|T|o|p| 
diff --git a/src/testdir/test_popupwin.vim b/src/testdir/test_popupwin.vim
index abae5db..9471857 100644
--- a/src/testdir/test_popupwin.vim
+++ b/src/testdir/test_popupwin.vim
@@ -420,6 +420,15 @@
 	  call feedkeys("\<F4>\<LeftMouse>\<LeftRelease>", "xt")
 	endfunc
 	map <silent> <F4> :call test_setmouse(3, 17)<CR>
+	func CreateWithMenuFilter()
+	  let winid = popup_create('barfoo', #{
+		\ close: 'button',
+		\ filter: 'popup_filter_menu',
+		\ border: [],
+		\ line: 1,
+		\ col: 40,
+		\ })
+	endfunc
   END
   call writefile(lines, 'XtestPopupClose')
   let buf = RunVimInTerminal('-S XtestPopupClose', #{rows: 10})
@@ -431,6 +440,14 @@
   call term_sendkeys(buf, ":call CloseWithClick()\<CR>")
   call VerifyScreenDump(buf, 'Test_popupwin_close_03', {})
 
+  call term_sendkeys(buf, ":call CreateWithMenuFilter()\<CR>")
+  call VerifyScreenDump(buf, 'Test_popupwin_close_04', {})
+
+  " We have to send the actual mouse code, feedkeys() would be caught the
+  " filter.
+  call term_sendkeys(buf, "\<Esc>[<0;47;1M")
+  call VerifyScreenDump(buf, 'Test_popupwin_close_05', {})
+
   " clean up
   call StopVimInTerminal(buf)
   call delete('XtestPopupClose')