android: add logging to see what's spamming editPrefs (#586)

Updates tailscale/tailscale#14125

Signed-off-by: kari-ts <kari@tailscale.com>

android/src/main/java/com/tailscale/ipn/App.kt

@@ -190,6 +190,7 @@ class App : UninitializedApp(), libtailscale.AppContext, ViewModelStoreOwner {
     applicationScope.launch {
       val hideDisconnectAction = MDMSettings.forceEnabled.flow.first()
     }
+    TSLog.init(this)
   }
 
   private fun initViewModels() {

android/src/main/java/com/tailscale/ipn/ui/localapi/Client.kt

@@ -4,6 +4,7 @@
 package com.tailscale.ipn.ui.localapi
 
 import android.content.Context
+import com.tailscale.ipn.App
 import com.tailscale.ipn.ui.model.BugReportID
 import com.tailscale.ipn.ui.model.Errors
 import com.tailscale.ipn.ui.model.Ipn
@@ -13,7 +14,6 @@ import com.tailscale.ipn.ui.model.StableNodeID
 import com.tailscale.ipn.ui.model.Tailcfg
 import com.tailscale.ipn.ui.util.InputStreamAdapter
 import com.tailscale.ipn.util.TSLog
-import com.tailscale.ipn.App
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.launch
@@ -69,9 +69,7 @@ class Client(private val scope: CoroutineScope) {
   private val TAG = Client::class.simpleName
 
   // Access libtailscale.Application lazily
-  private val app: libtailscale.Application by lazy {
-    App.get().getLibtailscaleApp()
-}
+  private val app: libtailscale.Application by lazy { App.get().getLibtailscaleApp() }
 
   fun start(options: Ipn.Options, responseHandler: (Result<Unit>) -> Unit) {
     val body = Json.encodeToString(options).toByteArray()
@@ -102,6 +100,14 @@ class Client(private val scope: CoroutineScope) {
   }
 
   fun editPrefs(prefs: Ipn.MaskedPrefs, responseHandler: (Result<Ipn.Prefs>) -> Unit) {
+    // Log the stack trace for debugging purposes for
+    // https://github.com/tailscale/tailscale/issues/14125
+    val stackTrace =
+        Thread.currentThread().stackTrace.joinToString("\n") { element ->
+          "at ${element.className}.${element.methodName}(${element.fileName}:${element.lineNumber})"
+        }
+    TSLog.v("editPrefs", "Called editPrefs with prefs: $prefs\nStack trace:\n$stackTrace")
+
     val body = Json.encodeToString(prefs).toByteArray()
     return patch(Endpoint.PREFS, body, responseHandler = responseHandler)
   }

android/src/main/java/com/tailscale/ipn/util/TSLog.kt

@@ -2,12 +2,18 @@
 // SPDX-License-Identifier: BSD-3-Clause
 package com.tailscale.ipn.util
 
+import android.content.Context
 import android.util.Log
 import libtailscale.Libtailscale
 
 object TSLog {
+  private lateinit var appContext: Context
   var libtailscaleWrapper = LibtailscaleWrapper()
 
+  fun init(context: Context) {
+    appContext = context.applicationContext
+  }
+
   fun d(tag: String?, message: String) {
     Log.d(tag, message)
     libtailscaleWrapper.sendLog(tag, message)
@@ -18,6 +24,13 @@ object TSLog {
     libtailscaleWrapper.sendLog(tag, message)
   }
 
+  fun v(tag: String?, message: String) {
+    if (isUnstableRelease()) {
+      Log.v(tag, message)
+      libtailscaleWrapper.sendLog(tag, message)
+    }
+  }
+
   // Overloaded function without Throwable because Java does not support default parameters
   @JvmStatic
   fun e(tag: String?, message: String) {
@@ -35,6 +48,15 @@ object TSLog {
     }
   }
 
+  private fun isUnstableRelease(): Boolean {
+    val versionName =
+        appContext.packageManager.getPackageInfo(appContext.packageName, 0).versionName
+
+    // Extract the middle number and check if it's odd
+    val middleNumber = versionName.split(".").getOrNull(1)?.toIntOrNull()
+    return middleNumber?.let { it % 2 == 1 } ?: false
+  }
+
   class LibtailscaleWrapper {
     public fun sendLog(tag: String?, message: String) {
       val logTag = tag ?: ""