patch 8.2.3999: redundant check for NUL byte

Problem:    Redundant check for NUL byte.
Solution:   Remove the check for a NUL byte. (closes #9471)
diff --git a/src/ex_docmd.c b/src/ex_docmd.c
index a0b9abf..7f2be49 100644
--- a/src/ex_docmd.c
+++ b/src/ex_docmd.c
@@ -3897,7 +3897,7 @@
     if (name == NULL)
 	return;
 
-    while (*name != NUL && *name == ':')
+    while (*name == ':')
 	name++;
     name = skip_range(name, TRUE, NULL);
 
diff --git a/src/version.c b/src/version.c
index 4f40aab..2c280af 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    3999,
+/**/
     3998,
 /**/
     3997,