File Bridge 1.13.1 — a VPN no longer looks like a wifi problem

Server 1.12.0 (unchanged) · Mac app 1.12.0 (unchanged) · Android app
1.11.1 (versionCode 14)

Android-only. One diagnostic fix, from a real failure.

The error blamed the wifi, and the wifi was fine

Connecting failed with:

Could not reach the Mac. Check both are on the same wifi and that File Bridge
is open with Start sharing pressed.

Both were true. Same SSID, sharing on, server answering 200 on its LAN IP with
the macOS firewall off. What was actually happening: a full-tunnel VPN on the
phone, which routes even 192.168.x.x out to the exit server — so a Mac two
metres away is unreachable, and every symptom points at the network.

That took a session to find, off a VPN badge visible in a screenshot.

Now it says so

A VPN holding the default route is detectable, not guesswork —
TRANSPORT_VPN on the active network answers it. When one is up:

• the connect error names the VPN first, and gives the fix that works: the VPN
  app's own "Allow LAN connections" (Proton, Mullvad, WireGuard and most
  others all have it), or disconnect;
• Settings shows the same warning while the VPN is up. It is a live condition,
  not a permission, so there is nothing to grant and nothing to remember.

With no VPN present, nothing changes. ACCESS_NETWORK_STATE was already
granted, so no new permission is requested.

Honest note

The detection uses the documented API and the string is compiled into the APK,
but the warning has not yet been seen on a screen with a VPN up — that needs a
device with one running. It is listed under "not verified" in HANDOFF.md.

Installing

Attached FileBridge-1.11.1.apk, versionCode 14 — upgrades in place. The Mac
side does not change; server 1.12.0 is still current.