diff --git a/src/nvim/testdir/test_tagjump.vim b/src/nvim/testdir/test_tagjump.vim
index 231d006da7..7a1a0132b3 100644
--- a/src/nvim/testdir/test_tagjump.vim
+++ b/src/nvim/testdir/test_tagjump.vim
@@ -1523,4 +1523,77 @@ func Test_stag_close_window_on_error()
   set tags&
 endfunc
 
+" Test for 'tagbsearch' (binary search)
+func Test_tagbsearch()
+  " If a tags file header says the tags are sorted, but the tags are actually
+  " unsorted, then binary search should fail and linear search should work.
+  call writefile([
+        \ "!_TAG_FILE_ENCODING\tutf-8\t//",
+        \ "!_TAG_FILE_SORTED\t1\t/0=unsorted, 1=sorted, 2=foldcase/",
+        \ "third\tXfoo\t3",
+        \ "second\tXfoo\t2",
+        \ "first\tXfoo\t1"],
+        \ 'Xtags')
+  set tags=Xtags
+  let code =<< trim [CODE]
+    int first() {}
+    int second() {}
+    int third() {}
+  [CODE]
+  call writefile(code, 'Xfoo')
+
+  enew
+  set tagbsearch
+  call assert_fails('tag first', 'E426:')
+  call assert_equal('', bufname())
+  call assert_fails('tag second', 'E426:')
+  call assert_equal('', bufname())
+  tag third
+  call assert_equal('Xfoo', bufname())
+  call assert_equal(3, line('.'))
+  %bw!
+
+  set notagbsearch
+  tag first
+  call assert_equal('Xfoo', bufname())
+  call assert_equal(1, line('.'))
+  enew
+  tag second
+  call assert_equal('Xfoo', bufname())
+  call assert_equal(2, line('.'))
+  enew
+  tag third
+  call assert_equal('Xfoo', bufname())
+  call assert_equal(3, line('.'))
+  %bw!
+
+  " If a tags file header says the tags are unsorted, but the tags are
+  " actually sorted, then binary search should work.
+  call writefile([
+        \ "!_TAG_FILE_ENCODING\tutf-8\t//",
+        \ "!_TAG_FILE_SORTED\t0\t/0=unsorted, 1=sorted, 2=foldcase/",
+        \ "first\tXfoo\t1",
+        \ "second\tXfoo\t2",
+        \ "third\tXfoo\t3"],
+        \ 'Xtags')
+
+  set tagbsearch
+  tag first
+  call assert_equal('Xfoo', bufname())
+  call assert_equal(1, line('.'))
+  enew
+  tag second
+  call assert_equal('Xfoo', bufname())
+  call assert_equal(2, line('.'))
+  enew
+  tag third
+  call assert_equal('Xfoo', bufname())
+  call assert_equal(3, line('.'))
+  %bw!
+
+  call delete('Xtags')
+  call delete('Xfoo')
+  set tags& tagbsearch&
+endfunc
+
 " vim: shiftwidth=2 sts=2 expandtab
diff --git a/src/nvim/testdir/test_taglist.vim b/src/nvim/testdir/test_taglist.vim
index 68f9982e36..1a3d1986bf 100644
--- a/src/nvim/testdir/test_taglist.vim
+++ b/src/nvim/testdir/test_taglist.vim
@@ -36,6 +36,12 @@ func Test_taglist()
   call assert_equal('d', cmd[0]['kind'])
   call assert_equal('call cursor(3, 4)', cmd[0]['cmd'])
 
+  " Use characters with value > 127 in the tag extra field.
+  call writefile([
+	\ "vFoo\tXfoo\t4" .. ';"' .. "\ttypename:int\ta£££\tv",
+	\ ], 'Xtags')
+  call assert_equal('v', taglist('vFoo')[0].kind)
+
   call assert_fails("let l=taglist([])", 'E730:')
 
   call delete('Xtags')
@@ -221,6 +227,11 @@ func Test_format_error()
   endtry
   call assert_true(caught_exception)
 
+  " no field after the filename for a tag
+  call writefile(["!_TAG_FILE_ENCODING\tutf-8\t//",
+        \ "foo\tXfile"], 'Xtags')
+  call assert_fails("echo taglist('foo')", 'E431:')
+
   set tags&
   call delete('Xtags')
 endfunc