Codename One: understand warnings and SecurityException after upgrading from JDK23 to JDK27 - codenameone

Question

On May 2018, Codename One was moved to Android API Level 27.
Previously I loaded in the store the version 0.1 of an app built with Codename One, with the Android API Level 23 (that was the previous default).
Google is forcing all its developers to upgrade the APPs to the newer API before the 1st November 2018, that's why I submitted to the store, few days ago, the same app, without any code modification, built with the last version of Codename One.
Today I received the following crash protection report. My question is an help to understand all the warnings and the java.lang.SecurityException. My app doesn't require any special permission and don't ask permissions to the user during the running (it's a very simple app). Before upgrading the app to the API Level 27 I never got these warnings and this exception.
[EDT] 0:0:0,1 - Codename One revisions: 38629bb7dc1724677b602b7cf175bee9bf0d67c8
[EDT] 0:0:0,4 - WARNING: Theme sets the commandBehavior constant which is deprecated. Please update the theme to NOT include this theme constant. Using commandBehavior may cause your app to perform in unexpected ways. In particular, using SIDE command behavior in conjunction with Toolbar.setOnTopSideMenu(true) may result in runtime exceptions.
[EDT] 0:0:0,6 - WARNING: Display.setCommandBehavior() is deprecated, Using it may result in unexpected behaviour. In particular, using COMMAND_BEHAVIOR_SIDE_NAVIGATION in conjunction with Toolbar.setOnTopSideMenu(true) may result in runtime errors.
[EDT] 0:0:0,11 - STARTING of the app "Giorno per giorno" version 0.2
[EDT] 0:0:0,12 - Platform: Unknown
[EDT] 0:0:0,13 - Platform Name: and
[EDT] 0:0:0,15 - OS: Android
[EDT] 0:0:0,17 - OS Version: 8.0.0
[EDT] 0:0:0,19 - Display Width: 1080
[EDT] 0:0:0,20 - Display Height: 2150
[EDT] 0:0:0,22 - Device density: DENSITY_HD
[EDT] 0:0:0,23 - mese: 10
[EDT] 0:0:0,24 - giorno del mese: 19
[EDT] 0:0:0,36 - I'm trying to open the file /giorno-293.txt
[EDT] 0:0:0,38 - File opened successfully
[EDT] 0:0:0,38 - isNativeShareSupported: true
[EDT] 0:0:0,874 - Exception: java.lang.SecurityException - Permission Denial: starting Intent { act=android.intent.action.MAIN flg=0x10400000 cmp=com.huawei.android.launcher/.powersavemode.PowerSaveModeLauncher (has extras) } from ProcessRecord{e69f9b7 13566:cloud.amoremio.app.daybyday/u0a110} (pid=13566, uid=10110) not exported from uid 10072
java.lang.SecurityException: Permission Denial: starting Intent { act=android.intent.action.MAIN flg=0x10400000 cmp=com.huawei.android.launcher/.powersavemode.PowerSaveModeLauncher (has extras) } from ProcessRecord{e69f9b7 13566:cloud.amoremio.app.daybyday/u0a110} (pid=13566, uid=10110) not exported from uid 10072
at android.os.Parcel.readException(Parcel.java:1946)
at android.os.Parcel.readException(Parcel.java:1892)
at android.app.IActivityManager$Stub$Proxy.startActivity(IActivityManager.java:4373)
at android.app.Instrumentation.execStartActivity(Instrumentation.java:1631)
at android.app.Activity.startActivityForResult(Activity.java:4751)
at android.app.Activity.startActivityForResult(Activity.java:4691)
at com.codename1.impl.android.CodenameOneActivity.startActivityForResult(CodenameOneActivity.java:576)
at android.app.Activity.startActivity(Activity.java:5112)
at android.app.Activity.startActivity(Activity.java:5080)
at com.codename1.impl.android.CodenameOneActivity.startActivity(CodenameOneActivity.java:590)
at com.codename1.impl.android.d.W(AndroidImplementation.java:1311)
at com.codename1.s.q.o(Display.java:1546)
at com.codename1.s.ab.c(MenuBar.java:1413)
at com.codename1.s.aj.c(SideMenuBar.java:704)
at com.codename1.s.u.c(Form.java:2748)
at com.codename1.s.q.a(Display.java:2015)
at com.codename1.s.q.j(Display.java:1043)
at com.codename1.s.q.i(Display.java:961)
at com.codename1.s.ai.run(RunnableWrapper.java:120)
at com.codename1.impl.b$1.run(CodenameOneThread.java:60)
at java.lang.Thread.run(Thread.java:784)
[EDT] 0:0:0,877 - Exception in Giorno per giorno version 0.2
[EDT] 0:0:0,877 - OS and
[EDT] 0:0:0,878 - Error java.lang.SecurityException: Permission Denial: starting Intent { act=android.intent.action.MAIN flg=0x10400000 cmp=com.huawei.android.launcher/.powersavemode.PowerSaveModeLauncher (has extras) } from ProcessRecord{e69f9b7 13566:cloud.amoremio.app.daybyday/u0a110} (pid=13566, uid=10110) not exported from uid 10072
[EDT] 0:0:0,878 - Current Form null
[EDT] 0:0:0,879 - Exception: java.lang.SecurityException - Permission Denial: starting Intent { act=android.intent.action.MAIN flg=0x10400000 cmp=com.huawei.android.launcher/.powersavemode.PowerSaveModeLauncher (has extras) } from ProcessRecord{e69f9b7 13566:cloud.amoremio.app.daybyday/u0a110} (pid=13566, uid=10110) not exported from uid 10072
java.lang.SecurityException: Permission Denial: starting Intent { act=android.intent.action.MAIN flg=0x10400000 cmp=com.huawei.android.launcher/.powersavemode.PowerSaveModeLauncher (has extras) } from ProcessRecord{e69f9b7 13566:cloud.amoremio.app.daybyday/u0a110} (pid=13566, uid=10110) not exported from uid 10072
at android.os.Parcel.readException(Parcel.java:1946)
at android.os.Parcel.readException(Parcel.java:1892)
at android.app.IActivityManager$Stub$Proxy.startActivity(IActivityManager.java:4373)
at android.app.Instrumentation.execStartActivity(Instrumentation.java:1631)
at android.app.Activity.startActivityForResult(Activity.java:4751)
at android.app.Activity.startActivityForResult(Activity.java:4691)
at com.codename1.impl.android.CodenameOneActivity.startActivityForResult(CodenameOneActivity.java:576)
at android.app.Activity.startActivity(Activity.java:5112)
at android.app.Activity.startActivity(Activity.java:5080)
at com.codename1.impl.android.CodenameOneActivity.startActivity(CodenameOneActivity.java:590)
at com.codename1.impl.android.d.W(AndroidImplementation.java:1311)
at com.codename1.s.q.o(Display.java:1546)
at com.codename1.s.ab.c(MenuBar.java:1413)
at com.codename1.s.aj.c(SideMenuBar.java:704)
at com.codename1.s.u.c(Form.java:2748)
at com.codename1.s.q.a(Display.java:2015)
at com.codename1.s.q.j(Display.java:1043)
at com.codename1.s.q.i(Display.java:961)
at com.codename1.s.ai.run(RunnableWrapper.java:120)
at com.codename1.impl.b$1.run(CodenameOneThread.java:60)
at java.lang.Thread.run(Thread.java:784)

Answer 1

This seems to be a bug in the Huawei launcher. When a user presses the back button in the applications main form we minimize the application by default (as is the convention in Android). The minimize method is implemented as such on Android:
public boolean minimizeApplication() {
Intent startMain = new Intent(Intent.ACTION_MAIN);
startMain.addCategory(Intent.CATEGORY_HOME);
startMain.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startMain.putExtra("WaitForResult", Boolean.FALSE);
getContext().startActivity(startMain);
return true;
}
This essentially asks the system to go back "home". It doesn't require permissions or anything specific but it seems Huawei misconfigured their activity and this fails. I think this just means backing out of the app on these devices will fail. The user can probably still use the home button itself instead of the back button.
Unfortunately it seems Huawei don't have a public bug reporting system. Hopefully they'll fix this issue or a workaround will emerge.