fix(winfloat): last_status when changing split to floatwin

Problem: converting a split to a floatwin may not remove the last statusline
when needed. (e.g: 'ls' is 1)

Solution: call last_status/win_comp_pos in win_new_float, after win_remove.

Also fix float_pos formatting for screen snapshots so it doesn't give a nil
error for external windows.

Not an issue from this PR.

src/nvim/winfloat.c

@@ -100,8 +100,9 @@ win_T *win_new_float(win_T *wp, bool last, WinConfig fconfig, Error *err)
     int dir;
     winframe_remove(wp, &dir, NULL, NULL);
     XFREE_CLEAR(wp->w_frame);
-    win_comp_pos();  // recompute window positions
     win_remove(wp, NULL);
+    last_status(false);  // may need to remove last status line
+    win_comp_pos();  // recompute window positions
     win_append(lastwin_nofloating(NULL), wp, NULL);
   }
   wp->w_floating = true;

test/functional/api/window_spec.lua

@@ -3241,6 +3241,46 @@ describe('API/win', function()
         pcall_err(api.nvim_win_set_config, win, cfg)
       )
     end)
+
+    it('removes last statusline if needed', function()
+      local screen = Screen.new(30, 9)
+      command('set laststatus=1 | botright split')
+      screen:expect([[
+                                      |
+        {1:~                             }|*2
+        {2:[No Name]                     }|
+        ^                              |
+        {1:~                             }|*2
+        {3:[No Name]                     }|
+                                      |
+      ]])
+      api.nvim_win_set_config(0, { relative = 'editor', row = 0, col = 0, width = 4, height = 4 })
+      screen:expect([[
+        {4:^    }                          |
+        {11:~   }{1:                          }|*3
+        {1:~                             }|*4
+                                      |
+      ]])
+      command('quit | set laststatus=2 | botright split')
+      screen:expect([[
+                                      |
+        {1:~                             }|*2
+        {2:[No Name]                     }|
+        ^                              |
+        {1:~                             }|*2
+        {3:[No Name]                     }|
+                                      |
+      ]])
+      api.nvim_win_set_config(0, { relative = 'editor', row = 1, col = 5, width = 4, height = 4 })
+      screen:expect([[
+                                      |
+        {1:~    }{4:^    }{1:                     }|
+        {1:~    }{11:~   }{1:                     }|*3
+        {1:~                             }|*2
+        {2:[No Name]                     }|
+                                      |
+      ]])
+    end)
   end)
 
   describe('get_config', function()

test/functional/ui/float_spec.lua

@@ -7758,12 +7758,11 @@ describe('float window', function()
           screen:expect {
             grid = [[
           ## grid 1
-            [2:----------------------------------------]|*5
-            {5:[No Name] [+]                           }|
+            [2:----------------------------------------]|*6
             [3:----------------------------------------]|
           ## grid 2
             x                                       |
-            {0:~                                       }|*4
+            {0:~                                       }|*5
           ## grid 3
                                                     |
           ## grid 4

test/functional/ui/messages_spec.lua

@@ -2346,8 +2346,7 @@ describe('ui/ext_messages', function()
     screen:expect([[
                                                                                       |
       {1:~    }{4:^     }{1:                                                                      }|
-      {1:~                                                                               }|*21
-      {2:[No Name]                                                                       }|
+      {1:~                                                                               }|*22
     ]])
   end)
 

test/functional/ui/screen.lua

@@ -1795,9 +1795,14 @@ local function fmt_ext_state(name, state)
   elseif name == 'float_pos' then
     local str = '{\n'
     for k, v in pairs(state) do
-      str = str .. '  [' .. k .. '] = {' .. v[1]
-      for i = 2, #v do
-        str = str .. ', ' .. inspect(v[i])
+      str = str .. '  [' .. k .. '] = {'
+      if v.external then
+        str = str .. ' external = true '
+      else
+        str = str .. v[1]
+        for i = 2, #v do
+          str = str .. ', ' .. inspect(v[i])
+        end
       end
       str = str .. '};\n'
     end