fix(options): using :set fillchars should clear local value

2 files changed, 54 insertions, 33 deletions

diff --git a/src/nvim/option.c b/src/nvim/option.c
index d301b17265..ec5d4919ba 100644
--- a/src/nvim/option.c
+++ b/src/nvim/option.c
@@ -2665,14 +2665,19 @@ ambw_end:
     }
   } else if (varp == &curwin->w_p_lcs) {  // local 'listchars'
     errmsg = set_chars_option(curwin, varp, true);
-  } else if (varp == &p_fcs) {  // 'fillchars'
+  } else if (varp == &p_fcs) {  // global 'fillchars'
     errmsg = set_chars_option(curwin, varp, false);
-    if (!errmsg) {
+    if (errmsg == NULL) {
+      // The current window is set to use the global 'fillchars' value.
+      // So clear the window-local value.
+      if (!(opt_flags & OPT_GLOBAL)) {
+        clear_string_option(&curwin->w_p_fcs);
+      }
       FOR_ALL_TAB_WINDOWS(tp, wp) {
         set_chars_option(wp, &wp->w_p_fcs, true);
       }
+      redraw_all_later(NOT_VALID);
     }
-    redraw_all_later(NOT_VALID);
   } else if (varp == &curwin->w_p_fcs) {  // local 'fillchars'
     errmsg = set_chars_option(curwin, varp, true);
   } else if (varp == &p_cedit) {  // 'cedit'
diff --git a/test/functional/options/chars_spec.lua b/test/functional/options/chars_spec.lua
index aa54b8a04a..a082204980 100644
--- a/test/functional/options/chars_spec.lua
+++ b/test/functional/options/chars_spec.lua
@@ -67,36 +67,52 @@ describe("'fillchars'", function()
       shouldfail('eob:xy') -- two ascii chars
       shouldfail('eob:\255', 'eob:<ff>') -- invalid UTF-8
     end)
-    it('has global value', function()
-      screen:try_resize(50, 5)
-      insert("foo\nbar")
-      command('set laststatus=0')
-      command('1,2fold')
-      command('vsplit')
-      command('set fillchars=fold:x')
-      screen:expect([[
-        ^+--  2 lines: fooxxxxxxxx│+--  2 lines: fooxxxxxxx|
-        ~                        │~                       |
-        ~                        │~                       |
-        ~                        │~                       |
-                                                          |
-      ]])
-    end)
-    it('has local window value', function()
-      screen:try_resize(50, 5)
-      insert("foo\nbar")
-      command('set laststatus=0')
-      command('1,2fold')
-      command('vsplit')
-      command('setl fillchars=fold:x')
-      screen:expect([[
-        ^+--  2 lines: fooxxxxxxxx│+--  2 lines: foo·······|
-        ~                        │~                       |
-        ~                        │~                       |
-        ~                        │~                       |
-                                                          |
-      ]])
-    end)
+  end)
+  it('has global value', function()
+    screen:try_resize(50, 5)
+    insert("foo\nbar")
+    command('set laststatus=0')
+    command('1,2fold')
+    command('vsplit')
+    command('set fillchars=fold:x')
+    screen:expect([[
+      ^+--  2 lines: fooxxxxxxxx│+--  2 lines: fooxxxxxxx|
+      ~                        │~                       |
+      ~                        │~                       |
+      ~                        │~                       |
+                                                        |
+    ]])
+  end)
+  it('has window-local value', function()
+    screen:try_resize(50, 5)
+    insert("foo\nbar")
+    command('set laststatus=0')
+    command('1,2fold')
+    command('vsplit')
+    command('setl fillchars=fold:x')
+    screen:expect([[
+      ^+--  2 lines: fooxxxxxxxx│+--  2 lines: foo·······|
+      ~                        │~                       |
+      ~                        │~                       |
+      ~                        │~                       |
+                                                        |
+    ]])
+  end)
+  it('using :set clears window-local value', function()
+    screen:try_resize(50, 5)
+    insert("foo\nbar")
+    command('set laststatus=0')
+    command('setl fillchars=fold:x')
+    command('1,2fold')
+    command('vsplit')
+    command('set fillchars&')
+    screen:expect([[
+      ^+--  2 lines: foo········│+--  2 lines: fooxxxxxxx|
+      ~                        │~                       |
+      ~                        │~                       |
+      ~                        │~                       |
+                                                        |
+    ]])
   end)
 end)