patch 8.1.1739: deleted match highlighting not updated in other window

Problem:    Deleted match highlighting not updated in other window.
Solution:   Mark the window for refresh. (closes #4720)  Also fix that
            ambi-width check clears with wrong attributes.
diff --git a/src/testdir/dumps/Test_matchdelete_1.dump b/src/testdir/dumps/Test_matchdelete_1.dump
new file mode 100644
index 0000000..06b16b5
--- /dev/null
+++ b/src/testdir/dumps/Test_matchdelete_1.dump
@@ -0,0 +1,12 @@
+> +0&#ffffff0@74
+|~+0#4040ff13&| @73
+|~| @73
+|~| @73
+|~| @73
+|[+3#0000000&|N|o| |N|a|m|e|]| @47|0|,|0|-|1| @9|A|l@1
+|H+0&&|e|l@1|o| |V|i|m| |w|o|r|l|d| @59
+|~+0#4040ff13&| @73
+|~| @73
+|~| @73
+|[+1#0000000&|N|o| |N|a|m|e|]| |[|+|]| @43|1|,|1| @11|A|l@1
+|:+0&&|c|a|l@1| |m|a|t|c|h|d|e|l|e|t|e|(|m|i|d|,| |w|i|n|i|d|)| @45
diff --git a/src/testdir/test_match.vim b/src/testdir/test_match.vim
index 51c9016..07005b5 100644
--- a/src/testdir/test_match.vim
+++ b/src/testdir/test_match.vim
@@ -1,6 +1,8 @@
 " Test for :match, :2match, :3match, clearmatches(), getmatches(), matchadd(),
 " matchaddpos(), matcharg(), matchdelete(), and setmatches().
 
+source screendump.vim
+
 function Test_match()
   highlight MyGroup1 term=bold ctermbg=red guibg=red
   highlight MyGroup2 term=italic ctermbg=green guibg=green
@@ -251,4 +253,26 @@
   set hlsearch&
 endfunc
 
+func Test_matchdelete_other_window()
+  if !CanRunVimInTerminal()
+    throw 'Skipped: cannot make screendumps'
+  endif
+
+  let lines =<< trim END
+    call setline(1, 'Hello Vim world')
+    let mid = matchadd('Error', 'world', 1)
+    let winid = win_getid()
+    new
+  END
+  call writefile(lines, 'XscriptMatchDelete')
+  let buf = RunVimInTerminal('-S XscriptMatchDelete', #{rows: 12})
+  call term_wait(buf)
+  call term_sendkeys(buf, ":call matchdelete(mid, winid)\<CR>")
+  call VerifyScreenDump(buf, 'Test_matchdelete_1', {})
+
+  call StopVimInTerminal(buf)
+  call delete('XscriptMatchDelete')
+endfunc
+
+
 " vim: shiftwidth=2 sts=2 expandtab