patch 9.1.0340: Problem: Error with matchaddpos() and empty list

Problem:  Error with matchaddpos() and empty list
          (@rickhow)
Solution: Return early for an empty list

fixes: #14525
closes: #14563

Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/testdir/test_match.vim b/src/testdir/test_match.vim
index 1896158..eb77791 100644
--- a/src/testdir/test_match.vim
+++ b/src/testdir/test_match.vim
@@ -307,6 +307,7 @@
   " Why doesn't the following error have an error code E...?
   call assert_fails("call matchaddpos('Error', [{}])", 'E290:')
   call assert_equal(-1, matchaddpos('Error', test_null_list()))
+  call assert_equal(-1, matchaddpos('Error', []))
   call assert_fails("call matchaddpos('Error', [1], [], 1)", 'E745:')
   call assert_equal(-1, matchaddpos('Search', [[]]))
   call assert_fails("call matchaddpos('Search', [[{}]])", 'E728:')
@@ -433,5 +434,4 @@
   call StopVimInTerminal(buf)
 endfunc
 
-
 " vim: shiftwidth=2 sts=2 expandtab