patch 8.0.1512: warning for possibly using NULL pointer

Problem:    Warning for possibly using NULL pointer. (Coverity)
Solution:   Skip using the pointer if it's NULL.
diff --git a/src/ex_cmds.c b/src/ex_cmds.c
index 788e9eb..a4d6221 100644
--- a/src/ex_cmds.c
+++ b/src/ex_cmds.c
@@ -6918,7 +6918,7 @@
 		copy_option_part(&p, NameBuff, MAXPATHL, ",");
 		mustfree = FALSE;
 		rt = vim_getenv((char_u *)"VIMRUNTIME", &mustfree);
-		if (fullpathcmp(rt, NameBuff, FALSE) != FPC_SAME)
+		if (rt != NULL && fullpathcmp(rt, NameBuff, FALSE) != FPC_SAME)
 		{
 		    int		fcount;
 		    char_u	**fnames;
diff --git a/src/version.c b/src/version.c
index a9643ca..965df22 100644
--- a/src/version.c
+++ b/src/version.c
@@ -772,6 +772,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1512,
+/**/
     1511,
 /**/
     1510,