Segfaults when run normally, runs fine in Valgrind

ex17.c

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

char *names_addr = 0;
char *mails_addr = 0;

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

void die(struct Connection *conn, const char *message)
{
    if(errno) {
        perror(message);
    } else {
        printf("ERROR: %s\n", message);
    }
    Database_close(conn);
    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(conn, "Failed to load database.");

    int max_rows = conn->db->max_rows;
    int max_data = conn->db->max_data;
    printf("max_rows: %d; max_data: %d\n", max_rows, max_data);
    conn->db->rows = calloc(max_rows, sizeof(struct Address));
    names_addr = calloc(max_rows*max_data, sizeof(char));
    mails_addr = calloc(max_rows*max_data, sizeof(char));

    rc = fread(conn->db->rows, sizeof(struct Address)*max_rows,
               1, conn->file);
    if(rc != 1) die(conn, "Failed to load rows.");
    rc = fread(names_addr, max_rows*max_data*sizeof(char),
               1, conn->file);
    if(rc != 1) die(conn, "Failed to load names.");
    rc = fread(mails_addr, max_rows*max_data*sizeof(char),
               1, conn->file);
    if(rc != 1) die(conn, "Failed to load mails.");

    int i = 0;
    for(i = 0; i < conn->db->max_rows; i++) {
        struct Address addr = conn->db->rows[i];
        // then just assign it
        addr.name = names_addr+(conn->db->max_data*i);
        addr.email = mails_addr+(conn->db->max_data*i);
    }
}

struct Connection* Database_open(const char *filename, char mode)
{
    struct Connection *conn = calloc(1, sizeof(struct Connection));
    if(!conn) die(conn, "Memory error");

    conn->db = calloc(1, sizeof(struct Database));
    if(!conn->db) die(conn, "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(conn, "Failed to open the file");

    return 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(conn, "Failed to write database.");
    rc = fwrite(conn->db->rows, sizeof(struct Address)*conn->db->max_rows,
                1, conn->file);
    if(rc != 1) die(conn, "Failed to write rows.");
    rc = fwrite(names_addr, sizeof(char)*conn->db->max_rows*conn->db->max_data,

                1, conn->file);
    if(rc != 1) die(conn, "Failed to write names.");
    rc = fwrite(mails_addr, sizeof(char)*conn->db->max_rows*conn->db->max_data,
                1, conn->file);
    if(rc != 1) die(conn, "Failed to write mails.");

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

void Database_create(int max_data, int max_rows, struct Connection *conn)
{
    int i = 0;

    conn->db->max_rows = max_rows;
    conn->db->max_data = max_data;
    conn->db->rows = calloc(max_rows, sizeof(struct Address));
    names_addr = calloc(max_rows*max_data, sizeof(char));
    mails_addr = calloc(max_rows*max_data, sizeof(char));

    for(i = 0; i < max_rows; i++) {
        // make a prototype to initialize it
        struct Address addr = {.id = i, .set = 0};
        // then just assign it
        addr.name = names_addr+(max_data*i);
        addr.email = mails_addr+(max_data*i);

        conn->db->rows[i] = addr;
    }
}

void Database_set(struct Connection *conn, int id, const char *name, const char *email)
{
    struct Address *addr = &conn->db->rows[id];
    if(addr->set) die(conn, "Already set, delete it first");

    addr->set = 1;
    char *res = strncpy(addr->name, name, conn->db->max_data);
    // Work around design flaw in strncpy when the data is longer
    // maximum number of bytes
    addr->name[conn->db->max_data-1] = '\0';
    if(!res) die(conn, "Name copy failed");

    res = strncpy(addr->email, email, conn->db->max_data);
    addr->email[conn->db->max_data-1] = '\0';
    if(!res) die(conn, "Email copy failed");
    printf("Successfully set record %d(%d) with contents %s:%s\n",
            addr->id, addr->set, addr->name, addr->email);
}

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

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

void Database_delete(struct Connection *conn, int id)
{
    struct Address addr = {.id = id, .set = 0};
    conn->db->rows[id] = addr;
    printf("Row %d is set: %d\n", id, conn->db->rows[id].set);
}

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

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

        if(cur->set) {
            Address_print(cur);
            printf("Row %d is set: %d\n", cur->id, cur->set);
        }
    }
}

int main(int argc, char *argv[])
{
    if(argc < 3) die(NULL, "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(argc > 3 && action != 'c') {
        id = atoi(argv[3]);
        if(id >= conn->db->max_rows) {
            die(conn, "There's not that many records.");
        }
    }

    switch(action) {
        case 'c':
            if(argc != 5) die(conn, "Need max_data and max_rows to create db.");
            Database_create(atoi(argv[3]), atoi(argv[4]), conn);
            Database_write(conn);
            break;

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

            Database_get(conn, id);
            break;

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

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

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

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

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

    Database_close(conn);

    return 0;
}