fix(eval): winnrs of unfocusable/hidden windows #35474

Problem: various functions may return incorrect window numbers for unfocusable
or hidden windows.

Solution: fix the checks. Make sure current windows in non-current tabpages have
a window number.

Fixes #35453

src/nvim/eval/buffer.c

@@ -380,8 +380,8 @@ static void buf_win_common(typval_T *argvars, typval_T *rettv, bool get_nr)
   int winid;
   bool found_buf = false;
   FOR_ALL_WINDOWS_IN_TAB(wp, curtab) {
-    winnr += win_has_winnr(wp);
-    if (wp->w_buffer == buf) {
+    winnr += win_has_winnr(wp, curtab);
+    if (wp->w_buffer == buf && (!get_nr || win_has_winnr(wp, curtab))) {
       found_buf = true;
       winid = wp->handle;
       break;

src/nvim/eval/window.c

@@ -38,9 +38,11 @@ static const char *e_invalwindow = N_("E957: Invalid window number");
 static const char e_cannot_resize_window_in_another_tab_page[]
   = N_("E1308: Cannot resize a window in another tab page");
 
-bool win_has_winnr(win_T *wp)
+bool win_has_winnr(win_T *wp, tabpage_T *tp)
+  FUNC_ATTR_NONNULL_ALL
 {
-  return wp == curwin || (!wp->w_config.hide && wp->w_config.focusable);
+  return (wp == (tp == curtab ? curwin : tp->tp_curwin))
+         || (!wp->w_config.hide && wp->w_config.focusable);
 }
 
 static int win_getid(typval_T *argvars)
@@ -54,10 +56,11 @@ static int win_getid(typval_T *argvars)
     return 0;
   }
 
+  tabpage_T *tp = NULL;
   if (argvars[1].v_type == VAR_UNKNOWN) {
+    tp = curtab;
     wp = firstwin;
   } else {
-    tabpage_T *tp = NULL;
     int tabnr = (int)tv_get_number(&argvars[1]);
     FOR_ALL_TABS(tp2) {
       if (--tabnr == 0) {
@@ -75,7 +78,7 @@ static int win_getid(typval_T *argvars)
     }
   }
   for (; wp != NULL; wp = wp->w_next) {
-    if ((winnr -= win_has_winnr(wp)) == 0) {
+    if ((winnr -= win_has_winnr(wp, tp)) == 0) {
       return wp->handle;
     }
   }
@@ -123,9 +126,9 @@ static int win_id2win(typval_T *argvars)
 
   FOR_ALL_WINDOWS_IN_TAB(wp, curtab) {
     if (wp->handle == id) {
-      return (win_has_winnr(wp) ? nr : 0);
+      return (win_has_winnr(wp, curtab) ? nr : 0);
     }
-    nr += win_has_winnr(wp);
+    nr += win_has_winnr(wp, curtab);
   }
   return 0;
 }
@@ -296,7 +299,7 @@ static int get_winnr(tabpage_T *tp, typval_T *argvar)
       semsg(_(e_invexpr2), arg);
       nr = 0;
     }
-  } else if (!win_has_winnr(twin)) {
+  } else if (!win_has_winnr(twin, tp)) {
     nr = 0;
   }
 
@@ -307,7 +310,7 @@ static int get_winnr(tabpage_T *tp, typval_T *argvar)
   nr = 0;
   win_T *wp = (tp == curtab) ? firstwin : tp->tp_firstwin;
   for (; wp != NULL; wp = wp->w_next) {
-    nr += win_has_winnr(wp);
+    nr += win_has_winnr(wp, tp);
     if (wp == twin) {
       break;
     }
@@ -423,11 +426,11 @@ void f_getwininfo(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
     tabnr++;
     int16_t winnr = 0;
     FOR_ALL_WINDOWS_IN_TAB(wp, tp) {
-      winnr += win_has_winnr(wp);
+      winnr += win_has_winnr(wp, tp);
       if (wparg != NULL && wp != wparg) {
         continue;
       }
-      dict_T *const d = get_win_info(wp, tabnr, winnr);
+      dict_T *const d = get_win_info(wp, tabnr, win_has_winnr(wp, tp) ? winnr : 0);
       tv_list_append_dict(rettv->vval.v_list, d);
       if (wparg != NULL) {
         // found information about a specific window
@@ -842,7 +845,7 @@ void f_winrestcmd(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
   for (int i = 0; i < 2; i++) {
     int winnr = 1;
     FOR_ALL_WINDOWS_IN_TAB(wp, curtab) {
-      if (!win_has_winnr(wp)) {
+      if (!win_has_winnr(wp, curtab)) {
         continue;
       }
       snprintf(buf, sizeof(buf), "%dresize %d|", winnr,

src/nvim/window.c

@@ -7501,11 +7501,13 @@ void win_get_tabwin(handle_T id, int *tabnr, int *winnr)
   FOR_ALL_TABS(tp) {
     FOR_ALL_WINDOWS_IN_TAB(wp, tp) {
       if (wp->handle == id) {
-        *winnr = wnum;
-        *tabnr = tnum;
+        if (win_has_winnr(wp, tp)) {
+          *winnr = wnum;
+          *tabnr = tnum;
+        }
         return;
       }
-      wnum += win_has_winnr(wp);
+      wnum += win_has_winnr(wp, tp);
     }
     tnum++;
     wnum = 1;

test/functional/ui/float_spec.lua

@@ -9,6 +9,7 @@ local command, feed_command = n.command, n.feed_command
 local eval = n.eval
 local eq = t.eq
 local neq = t.neq
+local matches = t.matches
 local expect = n.expect
 local exec = n.exec
 local exec_lua = n.exec_lua
@@ -899,14 +900,54 @@ describe('float window', function()
   end)
 
   it('non-visible/focusable are not assigned a window number', function()
-    local win = api.nvim_open_win(0, false, { relative = 'editor', width = 2, height = 2, row = 2, col = 2, focusable = false })
+    command('tabnew')
+    local tp = api.nvim_get_current_tabpage()
+    local split_win = api.nvim_get_current_win()
+    local float_buf = api.nvim_create_buf(true, true)
+    local win = api.nvim_open_win(float_buf, false, { relative = 'editor', width = 2, height = 2, row = 2, col = 2, focusable = false })
     api.nvim_open_win(0, false, { relative = 'editor', width = 2, height = 2, row = 2, col = 2, hide = true })
     api.nvim_open_win(0, false, { relative = 'editor', width = 2, height = 2, row = 2, col = 2 })
+
     eq(2, fn.winnr('$'))
     eq(0, fn.win_id2win(win))
+    eq(0, fn.getwininfo(win)[1].winnr)
+    eq({ 0, 0 }, fn.win_id2tabwin(win))
+    eq(2, fn.tabpagewinnr(2, '$'))
+    eq(0, fn.win_getid(3))
+    eq(0, fn.win_getid(3, 2))
+    eq(-1, fn.bufwinnr(float_buf))
+    eq(win, fn.bufwinid(float_buf)) -- bufwinid unaffected.
+    eq(nil, fn.winrestcmd():match('3resize'))
+
     -- Unless it is the current window.
     api.nvim_set_current_win(win)
-    eq({ 3, 3 }, { fn.winnr(), fn.win_id2win(win) })
+    eq(3, fn.winnr('$'))
+    eq(3, fn.winnr())
+    eq(3, fn.win_id2win(win))
+    eq(3, fn.getwininfo(win)[1].winnr)
+    eq({ 2, 3 }, fn.win_id2tabwin(win))
+    eq(3, fn.tabpagewinnr(2, '$'))
+    eq(3, fn.tabpagewinnr(2))
+    eq(win, fn.win_getid(3))
+    eq(win, fn.win_getid(3, 2))
+    eq(3, fn.bufwinnr(float_buf))
+    matches('3resize', fn.winrestcmd())
+
+    -- When switching tabpages it should still have a winnr, as it's current in the other tabpage.
+    command('tabfirst')
+    eq({ 2, 3 }, fn.win_id2tabwin(win))
+    eq(3, fn.getwininfo(win)[1].winnr)
+    eq(win, fn.win_getid(3, 2))
+    eq(3, fn.tabpagewinnr(2, '$'))
+    eq(3, fn.tabpagewinnr(2))
+
+    -- ...but not if it's non-current in that tabpage.
+    api.nvim_tabpage_set_win(tp, split_win)
+    eq({ 0, 0 }, fn.win_id2tabwin(win))
+    eq(0, fn.getwininfo(win)[1].winnr)
+    eq(0, fn.win_getid(3, 2))
+    eq(2, fn.tabpagewinnr(2, '$'))
+    eq(1, fn.tabpagewinnr(2))
   end)
 
   it('no crash for unallocated relative window grid', function()