patch 8.1.1816: cannot use a user defined function as a method
Problem: Cannot use a user defined function as a method.
Solution: Pass the base as the first argument to the user defined function
after "->". (partly by FUJIWARA Takuya)
diff --git a/src/testdir/sautest/autoload/foo.vim b/src/testdir/sautest/autoload/foo.vim
index d7dcd5c..298e727 100644
--- a/src/testdir/sautest/autoload/foo.vim
+++ b/src/testdir/sautest/autoload/foo.vim
@@ -5,3 +5,7 @@
func foo#bar.echo()
let g:called_foo_bar_echo += 1
endfunc
+
+func foo#addFoo(head)
+ return a:head .. 'foo'
+endfunc