LocationUpdated could never be called leading to GClueSimple API hang forever

[ilya-fedin]

Operating System

NixOS

XDG Desktop Portal version

1.18

XDG Desktop Portal version (Other)

No response

Desktop Environment

Plasma

Desktop Environment (Other)

No response

Expected Behavior

g_clue_simple_new_sync returns

Current Behavior

gclue_simple_new_sync hangs forever

Steps to Reproduce

#include <geoclue.h>

int main(int argc, char *argv[]) {
        g_autoptr(GClueSimple) simple = gclue_simple_new_sync("geoclue-where-am-i", GCLUE_ACCURACY_LEVEL_EXACT, NULL, NULL);
        GClueLocation *location = gclue_simple_get_location(simple);
        g_warning("Latitude: %f, Longitude: %f", gclue_location_get_latitude(location), gclue_location_get_longitude(location));
        return 0;
}

Anything else we should know?

The cause seem to be early returns in

xdg-desktop-portal/src/location.c

Line 156 in 6b95613

location_updated (GeoclueClient *client,

If the location is unknown, the signal is never emitted and GClueSimple hangs forever. I believe portal should emit the singal at least once.

[swick]

So I guess GeoClue always emits this signal at least once? Technically I don't think we ever had that guarantee but I think it would make sense in location_session_start to block until we have the first location update and then raise an error to the client if the GeoClue call failed.

[ilya-fedin]

No, it seem to be never emitted now that most systems have only MLS as location source and MLS doesn't work

[swick]

In that case I don't see why the behavior described in this issue is unexpected?

[ilya-fedin]

I expect the API to return some error in case the location is unknown so that I can handle that, e.g. fallback to other source or present a error to the user, as well as destroy the related resources. Right now it just never returns.