[BUG] Invalid drawable declarations generated when decompiling Instagram 207.0.0.39.120

Information

1. Apktool Version (apktool -version) - 2.6.0
2. Operating System (Mac, Linux, Windows) - Mac
3. APK From? (Playstore, ROM, Other) - Play Store

Facebook uses some unusual build system for their apps. Resources end up packaged inside the apk in a single folder named r, with some files referenced by more than one entry inside resources.arsc. While apktool does undo most of it correctly, it generates a file res/values/drawables.xml like this:

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <item type="drawable" name="chalk_brush">R||AQAEH1e24i3A|512|512|160</item>
    <item type="drawable" name="circle">R||AQAAoKYEg-_S|256|255|160</item>
    <item type="drawable" name="direct_dark_mode_inbox_reply_pill_background_gray">@drawable/direct_inbox_reply_pill_background_gray_night</item>
    <!-- more proper resource aliases -->
    <item type="drawable" name="direct_thread_gifs_place_holder_item_shhmode">@drawable/direct_thread_gifs_place_holder_item_night</item>
    <item type="drawable" name="fr_frame">R||AQAAkUF_KkOv|1024|1024|160</item>
    <item type="drawable" name="fr_lut">R||AQAAyPlUeUNj|1024|32|160</item>
    <item type="drawable" name="frbw_frame">R||AQAAk2w7mYkq|1024|1024|160</item>
    <item type="drawable" name="frbw_lut">R||AQAB6iBI8j8n|1024|32|160</item>
    <item type="drawable" name="frbw_overlay">R||AQACuRw-mWCq|1024|1024|160</item>
    <item type="drawable" name="in_call_notif_tv_icon">R||AQAGKjMnng39|120|122|160</item>
    <item type="drawable" name="inline_searchbox_background_shhmode">@drawable/inline_search_box_background_night</item>
    <item type="drawable" name="input_background_shhmode">@drawable/input_background_night</item>
    <item type="drawable" name="instagram_add_filled_24">I1800B7</item>
    <item type="drawable" name="instagram_add_outline_24">I18007B</item>
    <!-- a whole lot more of these nonsensical lines -->
    <item type="drawable" name="ll_font">R||AQACveI2bHlA|160|96|160</item>
    <item type="drawable" name="ll_leaks">R||AQABjmVlm-FX|1024|1024|160</item>
    <item type="drawable" name="ll_lut">R||AQADDu-9mCiw|1024|32|160</item>
    <item type="drawable" name="ll_noise">R||AQADKNuSWsE5|1024|1024|160</item>
    <item type="drawable" name="marker">R||AQABJEwQfEtS|256|256|160</item>
    <item type="drawable" name="media_additional_reactors_circle_shhmode">@drawable/media_additional_reactors_circle_night</item>
    <item type="drawable" name="meme_emphasis">R||AQACINpbVTEL|1301|371|160</item>
    <item type="drawable" name="neon_bulb_asset">R||AQABxh689A9n|256|256|160</item>
    <item type="drawable" name="ps_lut">R||AQABHygJLIb3|1024|32|160</item>
    <item type="drawable" name="radial_asset">R||AQADhGZJhKUF|256|256|160</item>
    <item type="drawable" name="rainbow_brush">R||AQAAeJIP-Nxa|256|256|160</item>
    <item type="drawable" name="textedit_background_error_shhmode">@drawable/textedit_background_error_night</item>
    <item type="drawable" name="textedit_background_shhmode">@drawable/textedit_background_night</item>
    <item type="drawable" name="unified_inbox_message_mask_no_border_shhmode">@drawable/unified_inbox_message_mask_no_border_night</item>
    <item type="drawable" name="unified_inbox_message_mask_shhmode">@drawable/unified_inbox_message_mask_night</item>
    <item type="drawable" name="unified_inbox_my_message_mask_shhmode">@drawable/unified_inbox_my_message_mask_night</item>
    <item type="drawable" name="vhs_glitch_0">R||AQADL3Xyljfu|1024|1024|160</item>
    <item type="drawable" name="vhs_glitch_1">R||AQABaRWCTW4_|1024|1024|160</item>
    <item type="drawable" name="vhs_lut">R||AQABd-1upOoH|1024|128|160</item>
    <item type="drawable" name="APKTOOL_DUMMY_bd" />
    <item type="drawable" name="APKTOOL_DUMMY_105" />
    <item type="drawable" name="APKTOOL_DUMMY_199" />
    <item type="drawable" name="APKTOOL_DUMMY_19a" />
    <item type="drawable" name="APKTOOL_DUMMY_1d4" />
    <item type="drawable" name="APKTOOL_DUMMY_1d5" />
    <!-- and some more of these too — not sure why they're here at all -->
</resources>

Obviously, building this as is results in an app that crashes when it first tries to make use of a resource that decoded incorrectly.

I don’t know Android internals nearly well enough, but might it be that there’s some newer kind of resource reference in resources.arsc, and these are meant to be @drawable/something references?

Stacktrace/Logcat

10-04 00:33:21.495 22922 22922 D AndroidRuntime: Shutting down VM
10-04 00:33:21.497 22922 22922 E AndroidRuntime: FATAL EXCEPTION: main
10-04 00:33:21.497 22922 22922 E AndroidRuntime: Process: com.instagram.android, PID: 22922
10-04 00:33:21.497 22922 22922 E AndroidRuntime: java.lang.RuntimeException: Unable to start activity ComponentInfo{com.instagram.android/com.instagram.mainactivity.MainActivity}: android.view.InflateException: Binary XML file line #34: Binary XML file line #35: Error inflating class com.instagram.common.ui.base.IgSimpleImageView
10-04 00:33:21.497 22922 22922 E AndroidRuntime: 	at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3654)
10-04 00:33:21.497 22922 22922 E AndroidRuntime: 	at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3806)
10-04 00:33:21.497 22922 22922 E AndroidRuntime: 	at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:83)
10-04 00:33:21.497 22922 22922 E AndroidRuntime: 	at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)
10-04 00:33:21.497 22922 22922 E AndroidRuntime: 	at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)
10-04 00:33:21.497 22922 22922 E AndroidRuntime: 	at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2267)
10-04 00:33:21.497 22922 22922 E AndroidRuntime: 	at android.os.Handler.dispatchMessage(Handler.java:107)
10-04 00:33:21.497 22922 22922 E AndroidRuntime: 	at android.os.Looper.loop(Looper.java:237)
10-04 00:33:21.497 22922 22922 E AndroidRuntime: 	at android.app.ActivityThread.main(ActivityThread.java:8167)
10-04 00:33:21.497 22922 22922 E AndroidRuntime: 	at java.lang.reflect.Method.invoke(Native Method)
10-04 00:33:21.497 22922 22922 E AndroidRuntime: 	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:496)
10-04 00:33:21.497 22922 22922 E AndroidRuntime: 	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1100)
10-04 00:33:21.497 22922 22922 E AndroidRuntime: Caused by: android.view.InflateException: Binary XML file line #34: Binary XML file line #35: Error inflating class com.instagram.common.ui.base.IgSimpleImageView
10-04 00:33:21.497 22922 22922 E AndroidRuntime: Caused by: android.view.InflateException: Binary XML file line #35: Error inflating class com.instagram.common.ui.base.IgSimpleImageView
10-04 00:33:21.497 22922 22922 E AndroidRuntime: Caused by: java.lang.reflect.InvocationTargetException
10-04 00:33:21.497 22922 22922 E AndroidRuntime: 	at java.lang.reflect.Constructor.newInstance0(Native Method)
10-04 00:33:21.497 22922 22922 E AndroidRuntime: 	at java.lang.reflect.Constructor.newInstance(Constructor.java:343)
10-04 00:33:21.497 22922 22922 E AndroidRuntime: 	at android.view.LayoutInflater.createView(LayoutInflater.java:854)
...
10-04 00:33:21.497 22922 22922 E AndroidRuntime: 	at android.view.LayoutInflater.inflate(LayoutInflater.java:481)
10-04 00:33:21.497 22922 22922 E AndroidRuntime: 	at X.1Zj.A0P(:23)
10-04 00:33:21.497 22922 22922 E AndroidRuntime: 	at androidx.appcompat.app.AppCompatActivity.setContentView(:268435463)
10-04 00:33:21.497 22922 22922 E AndroidRuntime: 	at com.instagram.base.activity.BaseFragmentActivity.onCreate(:14)
10-04 00:33:21.497 22922 22922 E AndroidRuntime: 	at com.instagram.mainactivity.MainActivity.onCreate(:349)
10-04 00:33:21.497 22922 22922 E AndroidRuntime: 	at android.app.Activity.performCreate(Activity.java:7963)
...
10-04 00:33:21.497 22922 22922 E AndroidRuntime: 	at android.app.ActivityThread.main(ActivityThread.java:8167)
10-04 00:33:21.497 22922 22922 E AndroidRuntime: 	at java.lang.reflect.Method.invoke(Native Method)
10-04 00:33:21.497 22922 22922 E AndroidRuntime: 	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:496)
10-04 00:33:21.497 22922 22922 E AndroidRuntime: 	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1100)
10-04 00:33:21.497 22922 22922 E AndroidRuntime: Caused by: android.content.res.Resources$NotFoundException: Drawable com.instagram.android:drawable/instagram_arrow_left_outline_24 with resource ID #0x7f0804ab
10-04 00:33:21.497 22922 22922 E AndroidRuntime: Caused by: android.content.res.Resources$NotFoundException: Drawable com.instagram.android:drawable/instagram_arrow_left_pano_outline_24 with resource ID #0x7f0804ae
10-04 00:33:21.497 22922 22922 E AndroidRuntime: Caused by: android.content.res.Resources$NotFoundException: File I180158 from drawable resource ID #0x7f0804ae
10-04 00:33:21.497 22922 22922 E AndroidRuntime: 	at android.content.res.ResourcesImpl.loadDrawableForCookie(ResourcesImpl.java:999)
10-04 00:33:21.497 22922 22922 E AndroidRuntime: 	at android.content.res.ResourcesImpl.loadDrawable(ResourcesImpl.java:735)
10-04 00:33:21.497 22922 22922 E AndroidRuntime: 	at android.content.res.Resources.getDrawableForDensity(Resources.java:965)
10-04 00:33:21.497 22922 22922 E AndroidRuntime: 	at X.11v.getDrawableForDensity(:65)
10-04 00:33:21.497 22922 22922 E AndroidRuntime: 	at android.content.res.Resources.getDrawable(Resources.java:880)
10-04 00:33:21.497 22922 22922 E AndroidRuntime: 	at X.1Xt.A00(:33)
10-04 00:33:21.497 22922 22922 E AndroidRuntime: 	at X.1Xu.get(:18)
10-04 00:33:21.497 22922 22922 E AndroidRuntime: 	at android.content.res.ResourcesImpl.loadDrawable(ResourcesImpl.java:715)
...
10-04 00:33:21.498 22922 22922 E AndroidRuntime: 	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:496)
10-04 00:33:21.498 22922 22922 E AndroidRuntime: 	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1100)
10-04 00:33:21.498 22922 22922 E AndroidRuntime: Caused by: java.io.FileNotFoundException: I180158
10-04 00:33:21.498 22922 22922 E AndroidRuntime: 	at android.content.res.AssetManager.nativeOpenNonAsset(Native Method)
10-04 00:33:21.498 22922 22922 E AndroidRuntime: 	at android.content.res.AssetManager.openNonAsset(AssetManager.java:992)
10-04 00:33:21.498 22922 22922 E AndroidRuntime: 	at android.content.res.ResourcesImpl.loadDrawableForCookie(ResourcesImpl.java:983)
10-04 00:33:21.498 22922 22922 E AndroidRuntime: 	... 58 more

Steps to Reproduce

1. apktool d instagram.apk
2. apktool b instagram

Frameworks

If this APK is from an OEM ROM (Samsung, HTC, LG). Please attach framework files (.apks that live in /system/framework or /system/priv-app)

It is not.

APK

If this APK can be freely shared, please upload/attach a link to it.

https://www.apkmirror.com/apk/instagram/instagram-instagram/instagram-instagram-207-0-0-39-120-release/instagram-207-0-0-39-120-android-apk-download/download/

Questions to ask before submission

1. Have you tried apktool d, apktool b without changing anything? Yes, that’s exactly what I did.
2. If you are trying to install a modified apk, did you resign it? Yes.
3. Are you using the latest apktool version? Yes.

[iBotPeaches]

I appreciate the research you did as I read my email on this ticket @MartinDupont

[grishka]

Duplicating here from the chat. I worked around this by decompiling with --no-res, extracting the /r directory from the apk into /unknown in the project, and adding all the files under /r to unknownFiles in apktool.yml. This results in a fully working rebuilt apk.

Downside? I can’t modify the resources. Not that I intended to, anyway. This would most probably work with other Facebook apps (Facebook itself, Messenger, and probably WhatsApp) as well.

p.s. TIL that Android 11 is really picky about apks and requires 4-byte alignment and a v2 signature if you target it.