ext/trie/trie.c in tyler-trie-0.2.2 vs ext/trie/trie.c in tyler-trie-0.2.3

@@ -5,10 +5,11 @@
 #include <string.h>
 
 VALUE cTrie, cTrieNode;
 
 static TrieChar* stringToTrieChar(VALUE string) {
+    StringValue(string);
     return (TrieChar*) RSTRING(string)->ptr;
 }
 
 static void trie_free(SBTrie *sb_trie) {
     if(sb_trie)
@@ -146,10 +147,13 @@
 	}
     }
 }
 
 static VALUE trie_children(VALUE self, VALUE prefix) {
+    if(NIL_P(prefix))
+	return rb_ary_new();
+
     SBTrie *sb_trie;
     Data_Get_Struct(self, SBTrie, sb_trie);
 
     const TrieChar *sb_prefix = stringToTrieChar(prefix);
     
@@ -202,9 +206,12 @@
 	}
     }
 }
 
 static VALUE trie_children_with_values(VALUE self, VALUE prefix) {
+    if(NIL_P(prefix))
+	return rb_ary_new();
+
     SBTrie *sb_trie;
     Data_Get_Struct(self, SBTrie, sb_trie);
 
     const TrieChar *sb_prefix = stringToTrieChar(prefix);