fix(api): don't crash when the service connects after the API was closed

[MiMoHo]

fix(api): don't crash when the service connects after the API was closed

Problem

Host apps using this library keep crashing with:

java.lang.NullPointerException: Attempt to invoke interface method
'void com.nextcloud.android.sso.api.NextcloudAPI$ApiConnectedListener.onConnected()'
on a null object reference
    at com.nextcloud.android.sso.api.AidlNetworkRequest$1.onServiceConnected(AidlNetworkRequest.java:69)

Reported for example in nextcloud/notes-android#2622 (labeled "Upstream :: SSO").

Root cause

NextcloudAPI starts binding to the AccountManagerService asynchronously.
When the consumer calls NextcloudAPI#close() before the connection is
established (e.g. after a request error invalidates a cached API instance),
NetworkRequest#close() nulls the ApiConnectedListener — but
AidlNetworkRequest#unbindService() only called Context#unbindService()
when the connection was already established (mBound == true). The pending
ServiceConnection therefore stayed registered with the framework and later
delivered onServiceConnected() on the main thread, which invoked
onConnected() on the nulled callback and crashed the host app.

Fix

• Track whether a binding has been requested and always unbind in that case,
  so a not-yet-established connection is released on close() as well.
• Guard onServiceConnected() against the remaining race where close()
  runs on another thread while the connection callback is already being
  dispatched: capture the callback locally and ignore stale connections.

Tests

Three new unit tests in AidlNetworkRequestTest:

• the regular flow still invokes the callback,
• a stale onServiceConnected() after close() no longer throws
  (fails with exactly the reported NPE without the fix),
• close() before the connection is established unbinds the
  ServiceConnection (fails without the fix).

unitTests.returnDefaultValues = true was enabled so the plain JVM tests can
run connect(), which touches Intent/ComponentName. All existing tests
and the CI checks (test, assembleDebug, lib:lint, lib:detekt,
lib:spotlessKotlinCheck) pass locally.

AI disclosure

This contribution was developed with AI assistance (Claude Code, model
claude-fable-5). I have reviewed, tested and take responsibility for the
changes, in accordance with the Nextcloud AI contribution policy.

[codacy-production]

Up to standards ✅

🟢 Issues 0 issues

Results:
0 new issues

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🟢 Metrics 9 complexity

Metric	Results
Complexity	9

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