vim-patch:8.1.0133: tagfiles() can have duplicate entries

Problem:    tagfiles() can have duplicate entries.
Solution:   Simplify the filename to make checking for duplicates work better.
            Add a test. (Dominique Pelle, closes vim/vim#2979)
https://github.com/vim/vim/commit/46577b5e5445c4aaa1e7ae1764373d11dae71663

1 files changed, 24 insertions, 1 deletions

diff --git a/src/nvim/testdir/test_taglist.vim b/src/nvim/testdir/test_taglist.vim
index f4e939254a..ea0a6b9678 100644
--- a/src/nvim/testdir/test_taglist.vim
+++ b/src/nvim/testdir/test_taglist.vim
@@ -1,4 +1,4 @@
-" test 'taglist' function and :tags command
+" test taglist(), tagfiles() functions and :tags command
 
 func Test_taglist()
   call writefile([
@@ -74,3 +74,26 @@ func Test_tagsfile_without_trailing_newline()
 
   call delete('Xtags')
 endfunc
+
+func Test_tagfiles()
+  call assert_equal([], tagfiles())
+
+  call writefile(["FFoo\tXfoo\t1"], 'Xtags1')
+  call writefile(["FBar\tXbar\t1"], 'Xtags2')
+  set tags=Xtags1,Xtags2
+  call assert_equal(['Xtags1', 'Xtags2'], tagfiles())
+
+  help
+  let tf = tagfiles()
+  call assert_equal(1, len(tf))
+  call assert_equal(fnamemodify(expand('$VIMRUNTIME/doc/tags'), ':p:gs?\\?/?'),
+	\           fnamemodify(tf[0], ':p:gs?\\?/?'))
+  helpclose
+  call assert_equal(['Xtags1', 'Xtags2'], tagfiles())
+  set tags&
+  call assert_equal([], tagfiles())
+
+  call delete('Xtags1')
+  call delete('Xtags2')
+  bd
+endfunc