feat(tree): support long option args separated by equals sign

As of 1.8.0, support for this seems somewhat inconsistent though, but it
works for most. Notably it does not work for `--timefmt=foo`, but let's
just ignore that inconvenient fact.

Author: scop

completions/tree

@@ -2,8 +2,8 @@
 
 _comp_cmd_tree()
 {
-    local cur prev words cword
-    _init_completion || return
+    local cur prev words cword split
+    _init_completion -s || return
 
     case $prev in
         -!(-*)[LPIHT] | --filelimit | --timefmt | --help | --version)
@@ -23,6 +23,8 @@ _comp_cmd_tree()
             ;;
     esac
 
+    $split && return
+
     if [[ $cur == -* ]]; then
         COMPREPLY=($(compgen -W '$(_parse_help "$1")' -- "$cur"))
         return

test/t/test_tree.py

@@ -13,3 +13,7 @@ def test_fromfile(self, completion):
     @pytest.mark.complete("tree -", require_cmd=True)
     def test_options(self, completion):
         assert completion
+
+    @pytest.mark.complete("tree --sort=", require_cmd=True)
+    def test_equals_sign_split(self, completion):
+        assert completion