patch 9.0.1435: scrolling too many lines when 'wrap' and 'diff' are set

Problem:    Scrolling too many lines when 'wrap' and 'diff' are set.
Solution:   Only scroll by screenlines for 'diff' when 'wrap' is not set.
            (closes #12211)

src/move.c

@@ -1763,7 +1763,7 @@ scrolling_screenlines(int byfold UNUSED)
 	|| (byfold && hasAnyFolding(curwin))
 # endif
 # ifdef FEAT_DIFF
-	|| curwin->w_p_diff
+	|| (curwin->w_p_diff && !curwin->w_p_wrap)
 # endif
 	;
 }

src/testdir/test_diffmode.vim

@@ -1588,6 +1588,21 @@ func Test_diff_scroll()
   call StopVimInTerminal(buf)
 endfunc
 
+" This was scrolling too many lines.
+func Test_diff_scroll_wrap_on()
+  20new
+  40vsplit
+  call setline(1, map(range(1, 9), 'repeat(v:val, 200)'))
+  setlocal number diff so=0
+  redraw
+  normal! jj
+  call assert_equal(1, winsaveview().topline)
+  normal! j
+  call assert_equal(2, winsaveview().topline)
+  bwipe!
+  bwipe!
+endfunc
+
 " This was trying to update diffs for a buffer being closed
 func Test_diff_only()
   silent! lfile

src/version.c

@@ -695,6 +695,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1435,
 /**/
     1434,
 /**/