vim-patch:8.2.2518: 'listchars' should be window-local

Problem:    'listchars' should be window-local.
Solution:   Make 'listchars' global-local. (Yegappan Lakshmanan, Marco Hinz,
            closes vim/vim#5206, closes vim/vim#7850)
https://github.com/vim/vim/commit/eed9d46293f0842aad0d50ff3a526f9a48b12421

Nvim already has this feature, but it implements :set listchars the same
as :setglobal listchars, which is incorrect. Vim's implementation of
:set listchars is correct: using :set listchars clears local value.

1 files changed, 8 insertions, 3 deletions

diff --git a/src/nvim/option.c b/src/nvim/option.c
index 5dd7d708f9..d301b17265 100644
--- a/src/nvim/option.c
+++ b/src/nvim/option.c
@@ -2650,14 +2650,19 @@ ambw_end:
       }
       s = skip_to_option_part(s);
     }
-  } else if (varp == &p_lcs) {  // 'listchars'
+  } else if (varp == &p_lcs) {  // global 'listchars'
     errmsg = set_chars_option(curwin, varp, false);
-    if (!errmsg) {
+    if (errmsg == NULL) {
+      // The current window is set to use the global 'listchars' value.
+      // So clear the window-local value.
+      if (!(opt_flags & OPT_GLOBAL)) {
+        clear_string_option(&curwin->w_p_lcs);
+      }
       FOR_ALL_TAB_WINDOWS(tp, wp) {
         set_chars_option(wp, &wp->w_p_lcs, true);
       }
+      redraw_all_later(NOT_VALID);
     }
-    redraw_all_later(NOT_VALID);
   } else if (varp == &curwin->w_p_lcs) {  // local 'listchars'
     errmsg = set_chars_option(curwin, varp, true);
   } else if (varp == &p_fcs) {  // 'fillchars'