[core] IfRegionMaker find the wrong outBlock

[ewt45]

Issue details

jadx failed to decompiled a method in this smali class.

/* JADX WARN: Multi-variable type inference failed */
    /* JADX WARN: Removed duplicated region for block: B:10:0x0065  */
    /* JADX WARN: Removed duplicated region for block: B:8:0x0064 A[RETURN] */
    /*
        Code decompiled incorrectly, please refer to instructions dump.
    */
    protected void onCreate(Bundle bundle) {
        ViewFacade viewFacade;
        super.onCreate(bundle);
        ApplicationStateBase applicationState = getApplicationState();
        XServerComponent component = applicationState.getEnvironment().getComponent(XServerComponent.class);
        Class cls = (Class) getIntent().getSerializableExtra("facadeclass");
        if (cls != null) {
            try {
                viewFacade = (ViewFacade) cls.getDeclaredConstructor(XServer.class, ApplicationStateBase.class).newInstance(component.getXServer(), applicationState);
            } catch (Exception unused) {
                Assert.state(ENABLE_TRACING_METHODS);
            }
            getWindow().addFlags(128);
            getWindow().addFlags(4194304);
            setContentView(R.layout.main);
            if (checkForSuddenDeath()) {
                this.viewOfXServer = new ViewOfXServer(this, component.getXServer(), viewFacade, applicationState.getXServerViewConfiguration());
                this.periodicIabCheckTimer.start();
                return;
            }
            return;
        }
        viewFacade = null;
        getWindow().addFlags(128);
        getWindow().addFlags(4194304);
        setContentView(R.layout.main);
        if (checkForSuddenDeath()) {
        }
    }

by looking into smali, the correct java code should be like

if (cls != null) {
    try {
        viewFacade = (ViewFacade) cls.getDeclaredConstructor(XServer.class, ApplicationStateBase.class).newInstance(component.getXServer(), applicationState);
    } catch (Exception unused) {
        Assert.state(ENABLE_TRACING_METHODS);
        viewFacade = null;
    }
} else {
    viewFacade = null;
}
getWindow().addFlags(128);
//...

the reason is that in IfRegionMaker.isBadBranchBlock(), else block has two predecessors and one of them is not in info.getMergedBlocks(). so else branch is thought as bad branch and extracted as out block.
in this case, else block indeed is in the end of then block, but is not 100% to be executed, so should still keep as else block.

Relevant log output or stacktrace

No response

Provide sample and class/method full name

sample smali

Jadx version

latest commit(f4849d6)

[skylot]

Issue with incorrect if restore is fixed in PR #2385.
But part with missing viewFacade = null; still not fixed. I will try to implement check and duplicate required block.
Also, it will nice to fix type inference issue 🙂

[ewt45]

the type inference warning only appears when this class's depedencies smali are missing. so maybe its not a big deal?
after de62954 , the type inference works correctly with the completed apk.

[skylot]

type inference warning only appears when this class's depedencies smali are missing. so maybe its not a big deal?

Sure, but this warning is about incorrect type for this, such warning is pointless, so I will just disable it 🤣