Segfaul out from debugger

I have a big problem with this program that simulates a database, everytime that i call the Database_set function, it return segfaul, but when i use gdb for debugging, everythings runs fine.

With more test, i found that everything work well during debugging if i create a new database (a file used for store datas) without reusing the already created databases, if i do things in this way, the call to Database_set won't return segfaul.

Out from debugger, this trick doesn't work and i get segfaul every time i try to access at line 122 addr->set, even if addr isn't a NULL pointer, because the previous call to malloc doesn't get error.

Here is the code :

#include <stdio.h>
#include <assert.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>

struct Address {
    int id;
    int set;
    char *name;
    char *email;
};

struct Database {
    int MAX_DATA;
    int MAX_ROWS;
    struct Address *rows;
};

struct Connection {
    FILE *file;
    struct Database *db;
};

void die(const char *message)
{
    if(errno) {
        perror(message);
    } else {
        printf("ERROR: %s\n", message);
    }

    exit(1);
}

void Address_print(struct Address *addr)
{
    printf("%d %s %s\n",
            addr->id, addr->name, addr->email);
}


void Database_load(struct Connection *conn)
{
    int rc = fread(conn->db, sizeof(struct Database), 1, conn->file);
    if(rc != 1) die("Failed to load database.");
}


struct Connection *Database_open(const char *filename, char mode)
{
    struct Connection *conn = malloc(sizeof(struct Connection));
    if(!conn) die("Memory error");

    conn->db = malloc(sizeof(struct Database));
    if(!conn->db) die("Memory error");

    if(mode == 'c') {
        conn->file = fopen(filename, "w");
    } else {
        conn->file = fopen(filename, "r+");

        if(conn->file) {
            Database_load(conn);
        }
    }

    if(!conn->file) die("Failed to open the file");

    return conn;
}

void Database_close(struct Connection *conn)
{
    if(conn) {
        if(conn->file) fclose(conn->file);
        if(conn->db) free(conn->db);
        free(conn);
    }
}

void Database_write(struct Connection *conn)
{
    rewind(conn->file);

    int rc = fwrite(conn->db, sizeof(struct Database), 1, conn->file);
    if(rc != 1) die("Failed to write database.");

    rc =fflush(conn->file);
    if(rc == -1) die("Cannot flush database.");
}

void Database_create(struct Connection *conn)
{
    printf("Please, insert max database rows limit .....");
    scanf("%d",&conn->db->MAX_ROWS);

    int i = 0;

    conn->db->rows = malloc(sizeof(struct Address)*conn->db->MAX_ROWS);
    if (!conn->db->rows) die("Memory error !");

    for (i = 0; i < conn->db->MAX_ROWS; i++) {

        /* struct Address addr = {.id = i, .set = 0};
        conn->db->rows[i] = addr; */

        conn->db->rows[i].id = 1;
        conn->db->rows[i].set = 0;
    }
}

void Database_set(struct Connection *conn, int id, const char *name, const char *email)
{

    printf("Please, insert max data limit ....");
     scanf("%d", &conn->db->MAX_DATA);


    struct Address *addr = &conn->db->rows[id];

    if(addr->set) die("Already set, delete it first");

    addr->set = 1;

    addr->name = malloc(conn->db->MAX_DATA);
    if(!addr->name) die("Memory error !");

    char *res = strcpy(addr->name, name);
    if(!res) die("Name copy failed");


    addr->email =malloc(conn->db->MAX_DATA);
    if(!addr->email) die("Memory error !");

    res = strcpy(addr->email, email);
    if(!res) die("Email copy failed");


}

void Database_get(struct Connection *conn, int id)
{
    struct Address *addr = &conn->db->rows[id];

    if(addr->set) {
        Address_print(addr);
    } else {
        die("ID is not set");
    }
}

void Database_delete(struct Connection *conn, int id)
{
    conn->db->rows[id].id = id;
    conn->db->rows[id].set = 0;
}

void Database_list(struct Connection *conn)
{
    int i = 0;
    struct Database *db = conn->db;

    for(i = 0; i < conn->db->MAX_ROWS; i++) {
        struct Address *cur = &db->rows[i];

        if(cur->set) {
            Address_print(cur);
        }
    }
}

int main(int argc, char *argv[])
{

    if(argc < 3) die("USAGE: ex17 <dbfile> <action> [action params]");

    char *filename = argv[1];
    char action = argv[2][0];

    struct Connection *conn = Database_open(filename, action);

    int id = 0;

    if (action != 'c') 
    {
        if (argc > 3) id = atoi(argv[4]);
        if (id >= conn->db->MAX_ROWS) die("There's not that many records.");
    }

    switch(action) {
        case 'c':
            Database_create(conn);
            Database_write(conn);
            break;

        case 'g':
            if(argc != 4) die("Need an id to get");
            Database_get(conn, id);
            break;

        case 's':
            if(argc != 6) die("Need id, name, email to set");

            Database_set(conn, id, argv[4], argv[5]);
            Database_write(conn);
            break;

        case 'd':
            if(argc != 4) die("Need id to delete");

            Database_delete(conn, id);
            Database_write(conn);
            break;

        case 'l':
            Database_list(conn);
            break;
        default:
            die("Invalid action, only: c=create, g=get, s=set, d=del, l=list");
    }

    Database_close(conn);

    return 0;
}