patch 8.2.2510: internal error when popup with mask is zero height or width

Problem:    Internal error when popup with mask is zero height or width.
Solution:   Bail out if width or height is zero. (closes #7831)

Author: brammool

src/popupwin.c

@@ -3331,8 +3331,12 @@ popup_update_mask(win_T *wp, int width, int height)
     char_u	*cells;
     int		row, col;
 
-    if (wp->w_popup_mask == NULL)
+    if (wp->w_popup_mask == NULL || width == 0 || height == 0)
+    {
+	vim_free(wp->w_popup_mask_cells);
+	wp->w_popup_mask_cells = NULL;
 	return;
+    }
     if (wp->w_popup_mask_cells != NULL
 	    && wp->w_popup_mask_height == height
 	    && wp->w_popup_mask_width == width)

src/testdir/test_popupwin.vim

@@ -825,6 +825,25 @@ func Test_popup_with_mask()
   " this was causing a crash
   call popup_create('test', #{mask: [[0, 0, 0, 0]]})
   call popup_clear()
+
+  " this was causing an internal error
+  enew
+  set nowrap
+  call repeat('x', &columns)->setline(1)
+  call prop_type_add('textprop', {})
+  call prop_add(1, 1, #{length: &columns, type: 'textprop'})
+  vsplit
+  let opts = popup_create('', #{textprop: 'textprop'})
+	\ ->popup_getoptions()
+	\ ->extend(#{mask: [[1, 1, 1, 1]]})
+  call popup_create('', opts)
+  redraw
+
+  close!
+  bwipe!
+  call prop_type_delete('textprop')
+  call popup_clear()
+  set wrap&
 endfunc
 
 func Test_popup_select()

src/version.c

@@ -750,6 +750,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    2510,
 /**/
     2509,
 /**/