patch 8.1.0212: preferred cursor column not set in interfaces

Problem:    Preferred cursor column not set in interfaces.
Solution:   Set w_set_curswant when setting the cursor. (David Hotham,
            closes #3060)
diff --git a/src/testdir/test_python3.vim b/src/testdir/test_python3.vim
index bb241da..69ad802 100644
--- a/src/testdir/test_python3.vim
+++ b/src/testdir/test_python3.vim
@@ -1,4 +1,4 @@
-" Test for python 2 commands.
+" Test for python 3 commands.
 " TODO: move tests from test88.in here.
 
 if !has('python3')
@@ -22,3 +22,17 @@
   bwipe!
   bwipe!
 endfunc
+
+func Test_set_cursor()
+  " Check that setting the cursor position works.
+  py3 import vim
+  new
+  call setline(1, ['first line', 'second line'])
+  normal gg
+  py3do vim.current.window.cursor = (1, 5)
+  call assert_equal([1, 6], [line('.'), col('.')])
+
+  " Check that movement after setting cursor position keeps current column.
+  normal j
+  call assert_equal([2, 6], [line('.'), col('.')])
+endfunc