patch 8.2.2643: various code not covered by tests

Problem:    Various code not covered by tests.
Solution:   Add a few more test. (Yegappan Lakshmanan, closes #7995)
diff --git a/src/version.c b/src/version.c
index fbe38b8..3d69e9c 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2643,
+/**/
     2642,
 /**/
     2641,