patch 8.2.2881: various pieces of code not covered by tests

Problem:    Various pieces of code not covered by tests.
Solution:   Add a few more tests. (Yegappan Lakshmanan, closes #8245)
diff --git a/src/version.c b/src/version.c
index 1c4bbfa..7fb1401 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2881,
+/**/
     2880,
 /**/
     2879,