LINUX STL string malloc 指针乱了

[yswang168]

有下面的一段代码，跟踪运行结果非常奇怪，
.................
if (pwa->HeadRule != NULL)
{ cout<<"headrule:"; pwa->HeadRule->print(); cout<<1<<endl;}


p = (char *)malloc(temp.size()+40);
if (pwa->HeadRule != NULL)
{ cout<<"headrule:"; pwa->HeadRule->print(); cout<<2<<endl;}


p1 = (char *)malloc(temp.size()+40);
if (pwa->HeadRule != NULL)
{ cout<<"headrule:"; pwa->HeadRule->print(); cout<<3<<endl;}

p2 = (char *)malloc(temp.size()+40);
if (pwa->HeadRule != NULL)
{ cout<<"headrule:"; pwa->HeadRule->print(); cout<<4<<endl;}

...............
这段的运行结果
headrule:1<=[a:1=2,not b:0=3]<=2 :- 4<=[a:1=5,not a:1=6]<=71
headrule:1<=[a:1=2,not b:0=3]<=2 :- 4<=[a:1=5,not a:1=6]<=72
headrule:1<=[a:1=2,not b:242044148160=3]<=2 :- 4<=[a:1=5,not a:1=6]<=73
～～～～～～～
这个地方的值莫名其妙地被修改了。
我是在Linux下使用了STL。

我把上面的代码换成
.............................
if (pwa->HeadRule != NULL)
{ cout<<"headrule:"; pwa->HeadRule->print(); cout<<"1 "<<endl;}

temp.assign("and(le(");
ltoa(pwa->lowerbound, tmp);
temp.append(tmp);
temp.append(",");
if (pwa->HeadRule != NULL)
{ cout<<"headrule:"; pwa->HeadRule->print(); cout<<"2 "<<endl;}

temp.append(str);
if (pwa->HeadRule != NULL)
{ cout<<"headrule:"; pwa->HeadRule->print(); cout<<"3 "<<endl;}
............................
结果与上面一样，输出：
headrule:1<=[a:1=2,not b:0=3]<=2 :- 4<=[a:1=5,not a:1=6]<=71
headrule:1<=[a:1=2,not b:0=3]<=2 :- 4<=[a:1=5,not a:1=6]<=72
headrule:1<=[a:1=2,not b:242044148160=3]<=2 :- 4<=[a:1=5,not a:1=6]<=73
~~~~~~~~~~~~~~也是莫名奇妙的被修改了（它是一个对象指针的成员）

[gogoDNA]

pwa->HeadRule->print();
这句干了什么???

[ewuby]

这代码只见树木不见森林，太难分析，路过~（不过可以考虑下数据溢出的可能性）