patch 8.2.2495: text jumps up and down when moving the cursor

Problem:    Text jumps up and down when moving the cursor in a small window
            with wrapping text and 'scrolloff' set.
Solution:   Adjust the computation of w_skipcol. (partly by Ghjuvan Lacambre,
            closes #7813)

src/move.c

@@ -1125,10 +1125,10 @@ curs_columns(
 	    n = curwin->w_wrow + so;
 	else
 	    n = p_lines;
-	if ((colnr_T)n >= curwin->w_height + curwin->w_skipcol / width)
+	if ((colnr_T)n >= curwin->w_height + curwin->w_skipcol / width - so)
 	    extra += 2;
 
-	if (extra == 3 || p_lines < so * 2)
+	if (extra == 3 || p_lines <= so * 2)
 	{
 	    // not enough room for 'scrolloff', put cursor in the middle
 	    n = curwin->w_virtcol / width;

src/testdir/test_breakindent.vim

@@ -634,7 +634,7 @@ func Test_breakindent19_sbr_nextpage()
   call s:compare_lines(expect, lines)
   " Scroll down one screen line
   setl scrolloff=5
-  norm! 5gj
+  norm! 6gj
   redraw!
   let lines = s:screen_lines(1, 20)
   let expect = [

src/version.c

@@ -750,6 +750,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    2495,
 /**/
     2494,
 /**/