fix(ui): set stc to empty in floatwin with minimal style (#21720)

fix(ui): set stc to emtpy in floatwin with minimal style

runtime/doc/api.txt

@@ -3042,10 +3042,10 @@ nvim_open_win({buffer}, {enter}, {*config})                  *nvim_open_win()*
                       Disables 'number', 'relativenumber', 'cursorline',
                       'cursorcolumn', 'foldcolumn', 'spell' and 'list'
                       options. 'signcolumn' is changed to `auto` and
-                      'colorcolumn' is cleared. The end-of-buffer region is
+                      'colorcolumn' is cleared. 'statuscolumn' is changed to
-                      hidden by setting `eob` flag of 'fillchars' to a space
+                      empty. The end-of-buffer region is hidden by setting
-                      char, and clearing the |hl-EndOfBuffer| region in
+                      `eob` flag of 'fillchars' to a space char, and clearing
-                      'winhighlight'.
+                      the |hl-EndOfBuffer| region in 'winhighlight'.
 
                   • border: Style of (optional) window border. This can either
                     be a string or an array. The string values are

src/nvim/api/win_config.c

@@ -114,8 +114,9 @@
 ///                    float where the text should not be edited. Disables
 ///                    'number', 'relativenumber', 'cursorline', 'cursorcolumn',
 ///                    'foldcolumn', 'spell' and 'list' options. 'signcolumn'
-///                    is changed to `auto` and 'colorcolumn' is cleared. The
+///                    is changed to `auto` and 'colorcolumn' is cleared.
-///                    end-of-buffer region is hidden by setting `eob` flag of
+///                    'statuscolumn' is changed to empty. The end-of-buffer
+///                     region is hidden by setting `eob` flag of
 ///                    'fillchars' to a space char, and clearing the
 ///                    |hl-EndOfBuffer| region in 'winhighlight'.
 ///   - border: Style of (optional) window border. This can either be a string

src/nvim/window.c

@@ -786,6 +786,12 @@ void win_set_minimal_style(win_T *wp)
     free_string_option(wp->w_p_cc);
     wp->w_p_cc = xstrdup("");
   }
+
+  // statuscolumn: cleared
+  if (wp->w_p_stc != NULL && *wp->w_p_stc != NUL) {
+    free_string_option(wp->w_p_stc);
+    wp->w_p_stc = xstrdup("");
+  }
 }
 
 void win_config_float(win_T *wp, FloatConfig fconfig)

test/functional/ui/float_spec.lua

@@ -1329,6 +1329,54 @@ describe('float window', function()
       end
     end)
 
+    it("would not break 'minimal' style with statuscolumn set", function()
+      command('set number')
+      command('set signcolumn=yes')
+      command('set colorcolumn=1')
+      command('set cursorline')
+      command('set foldcolumn=1')
+      command('set statuscolumn=%l%s%C')
+      command('hi NormalFloat guibg=#333333')
+      feed('ix<cr>y<cr><esc>gg')
+      meths.open_win(0, false, {relative='editor', width=20, height=4, row=4, col=10, style='minimal'})
+      if multigrid then
+        screen:expect{grid=[[
+        ## grid 1
+          [2:----------------------------------------]|
+          [2:----------------------------------------]|
+          [2:----------------------------------------]|
+          [2:----------------------------------------]|
+          [2:----------------------------------------]|
+          [2:----------------------------------------]|
+          [3:----------------------------------------]|
+        ## grid 2
+          {20:1}{21:  }{19: }{20:   }{22:^x}{21:                                }|
+          {14:2  }{19: }{14:   }{22:y}                                |
+          {14:3  }{19: }{14:   }{22: }                                |
+          {0:~                                       }|
+          {0:~                                       }|
+          {0:~                                       }|
+        ## grid 3
+                                                  |
+        ## grid 4
+          {15:x                   }|
+          {15:y                   }|
+          {15:                    }|
+          {15:                    }|
+        ]], float_pos={[4] = {{id = 1001}, "NW", 1, 4, 10, true}}}
+      else
+        screen:expect{grid=[[
+          {20:1}{21:  }{19: }{20:   }{22:^x}{21:                                }|
+          {14:2  }{19: }{14:   }{22:y}                                |
+          {14:3  }{19: }{14:   }{22: }  {15:x                   }          |
+          {0:~         }{15:y                   }{0:          }|
+          {0:~         }{15:                    }{0:          }|
+          {0:~         }{15:                    }{0:          }|
+                                                  |
+        ]]}
+      end
+    end)
+
     it('can have border', function()
       local buf = meths.create_buf(false, false)
       meths.buf_set_lines(buf, 0, -1, true, {' halloj! ',