Heap Damage Detected | C ++

Question

I got this " heap corruption detected " message after running this code:

 uli& uli::operator =(char* n) { char* buffer = new char[strlen(n)]; char* p; int op; int coef; strcpy(buffer, n); while(*buffer) { op = strlen(buffer) - 5; p = (op >= 0) ? op+buffer : buffer; coef = atoi(p); if(coef > 65535) coef = atoi(++p); push(head, coef); *p = '\0'; } delete buffer; // <- heap corruption detected return *this; } 

This is how I call the method:

 uli x; x = "9876123"; 

What does heap discovery mean?

Answer 1

“Heap corruption” usually means that you wrote to unallocated memory, damaging the data structures used to operate the memory allocator.

There may be more problems, but the first of them I see in this line:

 strcpy(buffer, n); 

This will write strlen(n) + 1 bytes to buffer , but buffer is only strlen(n) bytes (the extra byte is the final \0 ) Writing this extra byte leads to undefined behavior and can damage the heap.