patch 7.4.2158
Problem:    Result of getcompletion('', 'cscope') depends on previous
            completion. (Christian Brabandt)
Solution:   Call set_context_in_cscope_cmd().
diff --git a/src/evalfunc.c b/src/evalfunc.c
index b6f05b1..0095661 100644
--- a/src/evalfunc.c
+++ b/src/evalfunc.c
@@ -4240,6 +4240,13 @@
 	xpc.xp_pattern_len = (int)STRLEN(xpc.xp_pattern);
     }
 # endif
+#ifdef FEAT_CSCOPE
+    if (xpc.xp_context == EXPAND_CSCOPE)
+    {
+	set_context_in_cscope_cmd(&xpc, xpc.xp_pattern, CMD_cscope);
+	xpc.xp_pattern_len = (int)STRLEN(xpc.xp_pattern);
+    }
+#endif
 
     pat = addstar(xpc.xp_pattern, xpc.xp_pattern_len, xpc.xp_context);
     if ((rettv_list_alloc(rettv) != FAIL) && (pat != NULL))