Strange problem (or I'm stupid)

[arti]

char *EditUrl(char *url)
{
    InitApp();
    ULONG sigs = 0;
    struct ObjApp * obj = CreateUrlApp();
    STRPTR var;
    
    if (obj)
    {     
        set(obj->STR_Url, MUIA_String_Contents, (ULONG*)url);
        
        while (DoMethod(obj->App, MUIM_Application_NewInput, (IPTR)&sigs)
            != MUIV_Application_ReturnID_Quit)
        {
            if (sigs)
            {
                sigs = Wait(sigs | SIGBREAKF_CTRL_C);
                if (sigs & SIGBREAKF_CTRL_C)
                    break;
            }
        }
        
        get(obj->STR_Url, MUIA_String_Contents, &var);
        
        Printf(var);   <--- this properly prints new address
        
        DisposeApp(obj);
    }
    
    return var; 
}

int main(void)
{
      Printf(EditUrl("www.google.com")); <--null  only on <OS 3.5 ????
}

[ajk]

I have no experience programming with MUI in particular, but most likely the return value "var" is no longer valid after you have called DisposeApp(obj).

And it's a bit risky anyway since you haven't initialized var at all, so you might return an uninitialized pointer from EditUrl() to printf(), in the case where obj = NULL.

[arti]

You're right DisposeApp(obj) cleans var.

On OS3.9 and Aros, it works because of different memory managment, I guess.

[ajk]

Indeed. You just need to make a copy of the data to somewhere that you manage yourself.

[thomas]

Originally Posted by arti

You're right DisposeApp(obj) cleans var.

On OS3.9 and Aros, it works because of different memory managment, I guess.

You should always run MungWall and Enforcer on your testing machines. MungWall will fill freed memory with garbage, so that you always stumble across orphaned strings (or pointers or ...).

[alkis]

Minor nit-pick...

Printf in main should be Printf("%s\n", EditUrl("www.google.com"));