patch 8.2.4462: not enough testing for quickfix code

Problem:    Not enough testing for quickfix code.
Solution:   Add more tests. Fix uncovered problem. (Yegappan Lakshmanan,
            closes #9839)
diff --git a/src/window.c b/src/window.c
index ceb7d59..5e6fce8 100644
--- a/src/window.c
+++ b/src/window.c
@@ -4959,7 +4959,7 @@
 
 /*
  * Jump to the first open window in any tab page that contains buffer "buf",
- * if one exists.
+ * if one exists. First search in the windows present in the current tab page.
  * Returns a pointer to the window found, otherwise NULL.
  */
     win_T *