patch 8.2.1852: map() returing zero for NULL list is unexpected

Problem:    map() returing zero for NULL list is unexpected.
Solution:   Return the empty list. (closes #7133)
diff --git a/src/version.c b/src/version.c
index 934b822..266c7c1 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1852,
+/**/
     1851,
 /**/
     1850,