patch 8.2.1219: symlink not followed if dirname ends in //

Problem:    Symlink not followed if dirname ends in //.
Solution:   Resolve symlink earlier. (Tomáš Janoušek, closes #6454)
diff --git a/src/testdir/test_swap.vim b/src/testdir/test_swap.vim
index 7889d4b..5cd1018 100644
--- a/src/testdir/test_swap.vim
+++ b/src/testdir/test_swap.vim
@@ -377,4 +377,34 @@
   call delete('Xfile1')
 endfunc
 
+func Test_swap_symlink()
+  if !has("unix")
+    return
+  endif
+
+  call writefile(['text'], 'Xtestfile')
+  silent !ln -s -f Xtestfile Xtestlink
+
+  set dir=.
+
+  " Test that swap file uses the name of the file when editing through a
+  " symbolic link (so that editing the file twice is detected)
+  edit Xtestlink
+  call assert_match('Xtestfile\.swp$', s:swapname())
+  bwipe!
+
+  call mkdir('Xswapdir')
+  exe 'set dir=' . getcwd() . '/Xswapdir//'
+
+  " Check that this also works when 'directory' ends with '//'
+  edit Xtestlink
+  call assert_match('Xtestfile\.swp$', s:swapname())
+  bwipe!
+
+  set dir&
+  call delete('Xtestfile')
+  call delete('Xtestlink')
+  call delete('Xswapdir', 'rf')
+endfunc
+
 " vim: shiftwidth=2 sts=2 expandtab