Merge pull request #31597 from bfredl/deletionism

fix(wininfo): when freeing windows, free the lowest priority wininfo

2 files changed, 49 insertions, 4 deletions

diff --git a/src/nvim/window.c b/src/nvim/window.c
index 1c0d8c1027..fa2bfec138 100644
--- a/src/nvim/window.c
+++ b/src/nvim/window.c
@@ -5243,11 +5243,13 @@ void win_free(win_T *wp, tabpage_T *tp)
   // freed memory is re-used for another window.
   FOR_ALL_BUFFERS(buf) {
     WinInfo *wip_wp = NULL;
+    size_t pos_wip = kv_size(buf->b_wininfo);
     size_t pos_null = kv_size(buf->b_wininfo);
     for (size_t i = 0; i < kv_size(buf->b_wininfo); i++) {
       WinInfo *wip = kv_A(buf->b_wininfo, i);
       if (wip->wi_win == wp) {
         wip_wp = wip;
+        pos_wip = i;
       } else if (wip->wi_win == NULL) {
         pos_null = i;
       }
@@ -5255,11 +5257,12 @@ void win_free(win_T *wp, tabpage_T *tp)
 
     if (wip_wp) {
       wip_wp->wi_win = NULL;
-      // If there already is an entry with "wi_win" set to NULL it
-      // must be removed, it would never be used.
+      // If there already is an entry with "wi_win" set to NULL, only
+      // the first entry with NULL will ever be used, delete the other one.
       if (pos_null < kv_size(buf->b_wininfo)) {
-        free_wininfo(kv_A(buf->b_wininfo, pos_null), buf);
-        kv_shift(buf->b_wininfo, pos_null, 1);
+        size_t pos_delete = MAX(pos_null, pos_wip);
+        free_wininfo(kv_A(buf->b_wininfo, pos_delete), buf);
+        kv_shift(buf->b_wininfo, pos_delete, 1);
       }
     }
   }
diff --git a/test/functional/api/window_spec.lua b/test/functional/api/window_spec.lua
index 078d581b6f..028f0beb38 100644
--- a/test/functional/api/window_spec.lua
+++ b/test/functional/api/window_spec.lua
@@ -506,6 +506,48 @@ describe('API/win', function()
       assert_alive()
     end)
 
+    describe('after closing', function()
+      local buf, win0, win1, win2
+
+      before_each(function()
+        win0 = api.nvim_get_current_win()
+        command('new')
+        buf = api.nvim_get_current_buf()
+        win1 = api.nvim_get_current_win()
+        command('set numberwidth=10')
+        command('split')
+        win2 = api.nvim_get_current_win()
+        command('set numberwidth=15')
+        command('enew')
+        api.nvim_set_current_win(win1)
+        command('normal ix')
+        command('enew')
+        api.nvim_set_current_win(win0)
+        eq(4, api.nvim_get_option_value('numberwidth', {}))
+      end)
+
+      -- at this point buffer `buf` is current in no windows. Closing shouldn't affect its defaults
+      it('0 windows', function()
+        api.nvim_set_current_buf(buf)
+        eq(10, api.nvim_get_option_value('numberwidth', {}))
+      end)
+
+      it('1 window', function()
+        api.nvim_win_close(win1, false)
+
+        api.nvim_set_current_buf(buf)
+        eq(10, api.nvim_get_option_value('numberwidth', {}))
+      end)
+
+      it('2 windows', function()
+        api.nvim_win_close(win1, false)
+        api.nvim_win_close(win2, false)
+
+        api.nvim_set_current_buf(buf)
+        eq(10, api.nvim_get_option_value('numberwidth', {}))
+      end)
+    end)
+
     it('returns values for unset local options', function()
       eq(-1, api.nvim_get_option_value('scrolloff', { win = 0, scope = 'local' }))
     end)