patch 8.2.4204: screenpos() has non-zero row for invisible text

Problem:    screenpos() has non-zero row for invisible text.
Solution:   Only add the window row when the text is visible. (closes #9618)
diff --git a/src/move.c b/src/move.c
index b8e8780..f52e4c0 100644
--- a/src/move.c
+++ b/src/move.c
@@ -1262,12 +1262,15 @@
 	if (col >= wp->w_width)
 	    col = -1;
 	if (col >= 0 && row + rowoff <= wp->w_height)
+	{
 	    coloff = col - scol + wp->w_wincol + 1;
+	    row += W_WINROW(wp);
+	}
 	else
 	    // character is left, right or below of the window
 	    row = rowoff = scol = ccol = ecol = 0;
     }
-    *rowp = W_WINROW(wp) + row + rowoff;
+    *rowp = row + rowoff;
     *scolp = scol + coloff;
     *ccolp = ccol + coloff;
     *ecolp = ecol + coloff;
diff --git a/src/testdir/test_cursor_func.vim b/src/testdir/test_cursor_func.vim
index 965c704..bc12511 100644
--- a/src/testdir/test_cursor_func.vim
+++ b/src/testdir/test_cursor_func.vim
@@ -124,7 +124,7 @@
 	\ 'col': wincol + 7,
 	\ 'curscol': wincol + 7,
 	\ 'endcol': wincol + 7}, winid->screenpos(line('$'), 8))
-  call assert_equal({'row': winrow - 1, 'col': 0, 'curscol': 0, 'endcol': 0},
+  call assert_equal({'row': 0, 'col': 0, 'curscol': 0, 'endcol': 0},
         \ winid->screenpos(line('$'), 22))
 
   close
diff --git a/src/version.c b/src/version.c
index c75fe99..2208c1c 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    4204,
+/**/
     4203,
 /**/
     4202,