GDK ESourceRegistry Used to Work but Not Anymore - firefox-addon

Question

I'm developing Thunderbird addon that uses libedataserver.so.
Addon uses js-ctypes to call e_source_registry_new_sync from the above library. See below code:
var lib = ctypes.open("libedataserver-1.2.so.18");
var GCancellable = {};
GCancellable.cls = new ctypes.StructType("GCancellable");
var GError = {};
GError.cls = new ctypes.StructType("GError");
var ESourceRegistry = {};
ESourceRegistry.cls = new ctypes.StructType("ESourceRegistry");
ESourceRegistry.e_source_registry_new_sync =
lib.declare(
"e_source_registry_new_sync",
ctypes.default_abi,
ESourceRegistry.cls.ptr,
GCancellable.cls.ptr,
GError.cls.ptr.ptr);
//below line causes an error
var sourceRegistry = ESourceRegistry.e_source_registry_new_sync(null, null);
It works perfectly fine on Ubuntu however on Fedora 21 it prints below output and hangs:
(thunderbird:2735): GLib-GObject-WARNING **: cannot register existing type 'EDBusSource'
(thunderbird:2735): GLib-GObject-CRITICAL **: g_type_interface_add_prerequisite: assertion 'G_TYPE_IS_INTERFACE (interface_type)' failed
(thunderbird:2735): GLib-CRITICAL **: g_once_init_leave: assertion 'result != 0' failed
(thunderbird:2735): GLib-GObject-WARNING **: invalid cast from 'EDBusSourceProxy' to '<invalid>'
I'm using Fedora 21 with evolution-data-server 3.12.11-1.fc21.
Ubuntu uses evolution-data-server 3.12.10.
I developed simple C application that calls e_source_registry_new_sync and it works perfectly fine.
Can someone suggest what might be the reason of this issue?
#UPDATE:
I raised a Fedora bug. According to Fedora maintainers issue is caused by loading libedataserver twice (my code and evolution-ews):
The problem seems to be that thunderbird loads libedataserver-1.2.so.18 on its own, while the libcamelews.so has a runtime dependency on libedataserver-1.2.so, but this is not (in runtime) satisfied by the thunderbird-loaded libedataserver-1.2.so.18, thus it is loaded again, which breaks the GLib type system.
Please comment if there is something I can do from addon side.

Answer 1

You are asking about the error happening with this function: https://developer.gnome.org/libedataserver/stable/ESourceRegistry.html#e-source-registry-new-sync
The docs state that on error, NULL is returned and GError is set appropriately. I 'll test the code later and see what's up but I'll tell you here how to test it yourself.
GError is not an opque structure. Define it like this:
var GQuark = ctypes.uint32_t;
GError.cls = new ctypes.StructType('GError', [
{'domain': GQuark},
{'code': ctypes.int},
{'message': ctypes.char.ptr}
]);
Taken from here: https://gist.github.com/Noitidart/dbe54fcd7794c8ddff6f#file-_ff-addon-snippet-gdk_giolaunch-js-L22
Then set up your code to return error like this:
var error = GError.cls.ptr(); // can use `null` if we dont care to see error but we want to know what is happening so we can fix it
var sourceRegistry = ESourceRegistry.e_source_registry_new_sync(null, error.address());
if (sourceRegistry.isNull()) {
console.error('An error occured when calling e_source_registry_new_sync!');
console.info('ERROR DETAILS', 'Domain:', error.contents.domain.toString(), 'Code:', error.contents.code, 'Message:', error.contents.message.readString());
}
Then based on the error details look up that code and message and it will tell you what's up, then search StackOverflow or wherever for a solution to it if it's not obvious.