Segmentation Fault when trying to create a dynamically allocated char array - c++

Question

This is my code:
#include<iostream>
#include<string.h>
using namespace std;
class Zichara
{
private:
char *name;
int price;
void copy(const Zichara &from)
{
name = new char[strlen(from.name) + 1];
strcpy(name, from.name);
price = from.price;
}
public:
Zichara(const char *name, int price) {
this->name = new char[strlen(name) + 1];
strcpy(this->name, name);
this->price = price;
}
Zichara(const Zichara &from)
{
copy(from);
}
~Zichara() {
delete [] name;
}
friend class PlaninarskiDom;
};
class PlaninarskiDom {
private:
char name[15];
int prices[2];
char star;
bool isZichara;
Zichara *zich;
void copy(const PlaninarskiDom &from) {
strcpy(name, from.name);
star = from.star;
isZichara = from.isZichara;
zich = from.zich;
for(int i = 0; i < 2; i++) {
prices[i] = from.prices[i];
}
}
public:
PlaninarskiDom(const char *name = "", int prices = 0, const char star = '\0') {
strcpy(this->name, name);
this->star = star;
isZichara = 0;
zich = 0;
this->prices[0] = 0;
this->prices[1] = 0;
}
PlaninarskiDom(const char *name, int *prices, const char star) {
strcpy(this->name, name);
this->star = star;
isZichara = 0;
zich = 0;
this->prices[0] = prices[0];
this->prices[1] = prices[1];
}
PlaninarskiDom(const PlaninarskiDom &from) {
copy(from);
}
~PlaninarskiDom() {
delete [] zich;
}
PlaninarskiDom& operator = (const PlaninarskiDom &from) {
if(this == &from) return *this;
delete [] zich;
copy(from);
return *this;
}
void setZichara(Zichara &z) {
if(isZichara == 0) {
zich->copy(z);
isZichara = 1;
}
}
void operator --() {
if((int)star >= 65 && (int)star <= 70) {
++star;
if((int)star == 69) {
++star;
}
}
}
bool operator <= (char c) {
return star >= c;
}
void presmetajDnevenPrestoj(int day, int month, int &price) {
if(day < 0 || day > 31 || month < 0 || month > 12) {
throw 99;
}
else if(month >= 4 && month <= 8) {
price = prices[0];
}
else {
price = prices[1];
}
if(isZichara) {
price += zich->price;
}
}
friend ostream& operator << (ostream &, const PlaninarskiDom &);
};
ostream& operator << (ostream &os, const PlaninarskiDom &rhs) {
cout << rhs.name << " klasa:" << rhs.star << endl;
if(rhs.isZichara) {
cout << " so zichara" << endl;
}
return os;
}
int main(){
PlaninarskiDom p; //креирање на нов објект од класата планинарски дом
//во следниот дел се вчитуваат информации за планинарскиот дом
char imePlaninarskiDom[15],mestoZichara[30],klasa;
int ceni[12];
int dnevnakartaZichara;
bool daliZichara;
cin>>imePlaninarskiDom;
for (int i=0;i<2;i++) cin>>ceni[i];
cin>>klasa;
cin>>daliZichara;
//во следниот дел се внесуваат информации и за жичарата ако постои
if (daliZichara) {
cin>>mestoZichara>>dnevnakartaZichara;
PlaninarskiDom pom(imePlaninarskiDom,ceni,klasa);
Zichara r(mestoZichara,dnevnakartaZichara);
pom.setZichara(r);
p=pom;
}
else{
PlaninarskiDom *pok=new PlaninarskiDom(imePlaninarskiDom,ceni,klasa);
p=*pok;
}
//се намалува класата на планинарскиот дом за 2
--p;
--p;
int cena;
int den,mesec;
cin>>den>>mesec;
try{
p.presmetajDnevenPrestoj(den,mesec,cena); //тука се користи функцијата presmetajDnevenPrestoj
cout<<"Informacii za PlaninarskiDomot:"<<endl;
cout<<p;
if (p<='D')
cout<<"Planinarskiot dom za koj se vneseni informaciite ima klasa poniska ili ista so D\n";
cout<<"Cenata za "<<den<<"."<<mesec<<" e "<<cena; //се печати цената за дадениот ден и месец
}
catch (int){
cout<<"Mesecot ili denot e greshno vnesen!";
}
}
I ran a debugger on this code and it highlighted this:
name = new char[strlen(from.name) + 1];
This is the line of code as the line where the Seg Fault comes from.
This is an exercise for a class I have and I have to do it using dynamic memory allocation.
I've done this exact same thing many times before and there was no such error, so I have no idea why it is appearing, and I couldn't find an answer to this question on Google so far, so I apologize if somewhere out there it does exist.
Thanks everyone for the suggestions, this has been fixed!

Answer 1

You call this method:
void setZichara(Zichara &z) {
if(isZichara == 0) {
zich->copy(z);
isZichara = 1;
}
}
but you never allocate zich so you invoke UB calling a method on nullptr
Note: your PlaninarskiDom::copy() is incorrect as well, as you just assign pointer from another object aka shallow copy, which will lead to multiple destruction, though most probably you did not hit this issue yet. You should do deep copy instead or use std::shared_ptr is you plan to share ownership. Anyway if you are not limited by conditions using smart pointers are preferable when dealing with dynamically allocated objects. Or using special containers like std::vector or std::string which do proper memory management for you.