c++ - 二重連結リストの実装における「条件付きジャンプまたは移動は、初期化されていない値に依存する」

Question

Valgrind は、私が解決できない 2 つのエラーを示しています。次の関数で「条件付きジャンプまたは移動は初期化されていない値に依存します」というエラー メッセージが表示されますunplug_set。NULLチェックのせい？関数は、二重リンク リストから要素をアンプラグする必要があります。

void unplug_set(set * set_to_unplug){
        set * last_set = set_to_unplug->last;
        set * next_set = set_to_unplug->next;
        set_to_unplug->next = NULL;
        set_to_unplug->last = NULL;
148     if(last_set == NULL && next_set == NULL){ // only one element left
          ordered_by_score_set[set_to_unplug->weight] = NULL;
150     }else if(last_set == NULL){ // first set
          next_set->last = NULL;
          ordered_by_score_set[set_to_unplug->weight] = next_set;
        } else if (next_set == NULL) { // last set
          last_set->next = NULL;
        } else { // set in the middle
          last_set->next = next_set;
        next_set->last = last_set;
       }
}

Valgrind コマンド:

valgrind --dsymutil=yes --track-origins=yes ./set_program

出力：

==45085== Conditional jump or move depends on uninitialised value(s)
==45085==    at 0x100001A2C: unplug_set(set*) (:148)
                          ...
==45085==    by 0x100001294: main (Main.cpp:81)
==45085==  Uninitialised value was created by a heap allocation
==45085==    at 0xC713: malloc (vg_replace_malloc.c:274)
==45085==    by 0x63346: operator new(unsigned long) (in /usr/lib/libstdc++.6.0.9.dylib)
==45085==    by 0x100001E0C: add_set(int, int, unsigned int const*, unsigned short const*, int, unsigned int const*) (:57)
==45085==    by 0x10000127E: main (Main.cpp:39)
==45085==
==45085== Conditional jump or move depends on uninitialised value(s)
==45085==    at 0x100001A60: unplug_set(set*) (:150)
                          ...
==45085==    by 0x100001294: main (Main.cpp:81)
==45085==  Uninitialised value was created by a heap allocation
==45085==    at 0xC713: malloc (vg_replace_malloc.c:274)
==45085==    by 0x63346: operator new(unsigned long) (in /usr/lib/libstdc++.6.0.9.dylib)
==45085==    by 0x100001E0C: add_set(int, int, unsigned int const*, unsigned short const*, int, unsigned int const*) (:57)
==45085==    by 0x10000127E: main (Main.cpp:39)