My Lenovo A850 reboots almost every time I answer a call. Using adb I redirected the output to a file. Then I tried tracking the reason for the forced shut-down but I am not sure. The phone has a lot of Lenovo's pre-installed apks. I am posting the stack trace of what I think might be the error that causes the reboot.
Unfortunatelly I haven't found a decent site to host the stack trace so that you can see the whole thing but I'll give it a try soon.
I/AEE/AED (10955): $** *** *** *** *** *** *** *** Fatal *** *** *** *** *** *** *** **$
I/AEE/AED (10955): Build Info: 'ALPS.JB5.MP:A850_ROW_S116_130922:MT6582:S01,Lenovo/aupres_row/A850_ROW:4.2.2/JDQ39/A850_ROW_S116_130922.1379859786:user/release-keys'
I/AEE/AED (10955): Flavor Info: 'None'
I/AEE/AED (10955): Exception Log Time:[Wed Oct 29 21:22:51 EET 2014] [99110.120000]
I/AEE/AED (10955):
I/AEE/AED (10955): Java (JE)
I/AEE/AED (10955): system_server_crash
I/AEE/AED (10955): system_server
I/AEE/AED (10955): Process: system_server
I/AEE/AED (10955): Build: Lenovo/aupres_row/A850_ROW:4.2.2/JDQ39/A850_ROW_S116_130922.1379859786:user/release-keys
I/AEE/AED (10955):
I/AEE/AED (10955): java.lang.RuntimeException: Error receiving broadcast Intent { act=android.intent.action.USER_PRESENT flg=0x28000010 } in android.widget.ViewFlipper$1@42fa4908
I/AEE/AED (10955): at android.app.LoadedApk$ReceiverDispatcher$Args.run(LoadedApk.java:806)
I/AEE/AED (10955): at android.os.Handler.handleCallback(Handler.java:800)
I/AEE/AED (10955): at android.os.Handler.dispatchMessage(Handler.java:100)
I/AEE/AED (10955): at android.os.Looper.loop(Looper.java:194)
I/AEE/AED (10955): at com.android.server.ServerThread.run(SystemServer.java:1352)
I/AEE/AED (10955): Caused by: android.view.ViewRootImpl$CalledFromWrongThreadException: Only the original thread that created a view hierarchy can touch its views.
I/AEE/AED (10955): at android.view.ViewRootImpl.checkThread(ViewRootImpl.java:5351)
I/AEE/AED (10955): at android.view.ViewRootImpl.invalidateChildInParent(ViewRootImpl.java:1001)
I/AEE/AED (10955): at android.view.ViewGroup.invalidateChild(ViewGroup.java:4199)
I/AEE/AED (10955): at android.view.View.invalidate(View.java:10529)
I/AEE/AED (10955): at android.view.View.invalidateParentIfNeede
I/AEE/AED (10955): Backtrace of all threads:
I/AEE/AED (10955):
I/AEE/AED (10955): "NetdConnector" prio=5 Thread id=48 RUNNABLE
I/AEE/AED (10955): android.net.LocalSocketImpl.readba_native(Native Method)
I/AEE/AED (10955): android.net.LocalSocketImpl.access$400(LocalSocketImpl.java:29)
I/AEE/AED (10955): android.net.LocalSocketImpl$SocketInputStream.read(LocalSocketImpl.java:92)
I/AEE/AED (10955): com.android.server.NativeDaemonConnector.listenToSocket(NativeDaemonConnector.java:132)
I/AEE/AED (10955): com.android.server.NativeDaemonConnector.run(NativeDaemonConnector.java:90)
I/AEE/AED (10955): java.lang.Thread.run(Thread.java:838)
I/AEE/AED (10955):
I/AEE/AED (10955): "Thread-71" prio=5 Thread id=71 RUNNABLE
I/AEE/AED (10955): android.net.LocalSocketImpl.readba_native(Native Method)
I/AEE/AED (10955): android.net.LocalSocketImpl.access$400(LocalSocketImpl.java:29)
I/AEE/AED (10955): android.net.LocalSocketImpl$SocketInputStream.read(LocalSocketImpl.java:92)
I/AEE/AED (10955): libcore.io.Streams.readFully(Streams.java:81)
I/AEE/AED (10955): java.io.DataInputStream.readFully(DataInputStream.java:120)
I/AEE/AED (10955): com.mediatek.agps.MtkAgpsManagerService$MtkAgpsIO.readInt(MtkAgpsManagerService.java:2011)
I/AEE/AED (10955): com.mediatek.agps.MtkAgpsManagerService$MtkAgpsIO.run(MtkAgpsManagerService.java:1803)
I/AEE/AED (10955):
I/AEE/AED (10955): "AlarmManager
I/AEE/AED (10955): $** *** *** *** *** *** *** *** Fatal *** *** *** *** *** *** *** **$