defensive: NULL-check calloc results before dereferencing

Five sites allocated with calloc() and dereferenced the result on the
very next line. Under OOM the module would have segfaulted instead of
degrading. Each site now bails (or sends a Canceled D-Bus error, in
the agent path) when the allocation fails.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/e_mod_popup.c

@@ -523,6 +523,7 @@ e_iwd_popup_toggle(E_Gadcon_Client *gcc)
    if (!gcc || !e_iwd) return;
 
    Popup *p = calloc(1, sizeof(*p));
+   if (!p) return;
    _popup = p;
 
    p->gp = e_gadcon_popup_new(gcc, EINA_FALSE);

src/iwd/iwd_agent.c

@@ -73,6 +73,9 @@ _request_passphrase_cb(const Eldbus_Service_Interface *iface EINA_UNUSED,
                                      "No UI handler");
 
    Iwd_Agent_Request *req = calloc(1, sizeof(*req));
+   if (!req)
+     return eldbus_message_error_new(msg, "net.connman.iwd.Agent.Error.Canceled",
+                                     "Out of memory");
    req->agent = _self;
    req->msg   = eldbus_message_ref((Eldbus_Message *)msg);
    _self->cb(_self->data, req, path);

src/iwd/iwd_manager.c

@@ -63,6 +63,7 @@ iwd_manager_listener_add(Iwd_Manager *m, Iwd_Manager_Cb cb, void *data)
 {
    if (!m || !cb) return;
    Listener *l = calloc(1, sizeof(*l));
+   if (!l) return;
    l->cb = cb; l->data = data;
    m->listeners = eina_list_append(m->listeners, l);
 }

src/ui/wifi_auth.c

@@ -68,6 +68,7 @@ wifi_auth_prompt(Evas_Object *parent EINA_UNUSED, const char *ssid,
                  Wifi_Auth_Cb cb, void *data)
 {
    Auth_Ctx *c = calloc(1, sizeof(*c));
+   if (!c) return NULL;
    c->cb = cb; c->data = data;
 
    /* A floating top-level window so the popup is actually visible —

src/ui/wifi_hidden.c

@@ -104,6 +104,7 @@ void
 wifi_hidden_prompt(Evas_Object *parent EINA_UNUSED, Wifi_Hidden_Cb cb, void *data)
 {
    Hidden_Ctx *c = calloc(1, sizeof(*c));
+   if (!c) { if (cb) cb(data, NULL, NULL, EINA_FALSE); return; }
    c->cb = cb; c->data = data;
 
    /* Floating top-level so the popup actually shows. */