diff --git a/src/evalvars.c b/src/evalvars.c
index 22d39a7..eac66b2 100644
--- a/src/evalvars.c
+++ b/src/evalvars.c
@@ -319,7 +319,8 @@
 	{
 	    svar_T    *sv = ((svar_T *)si->sn_var_vals.ga_data) + idx;
 
-	    abort = abort || set_ref_in_item(sv->sv_tv, copyID, NULL, NULL);
+	    if (sv->sv_name != NULL)
+		abort = abort || set_ref_in_item(sv->sv_tv, copyID, NULL, NULL);
 	}
     }
 
diff --git a/src/version.c b/src/version.c
index 6c96175..4a4d65a 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2579,
+/**/
     2578,
 /**/
     2577,