feat: support config flags as low as 8 bytes (#2982)

Author: iBotPeaches

brut.apktool/apktool-lib/src/main/java/brut/androlib/res/decoder/ARSCDecoder.java

@@ -103,10 +103,10 @@ private ResPackage readTablePackage() throws IOException, AndrolibException {
         }
 
         String name = mIn.readNullEndedString(128, true);
-        /* typeStrings */mIn.skipInt();
-        /* lastPublicType */mIn.skipInt();
-        /* keyStrings */mIn.skipInt();
-        /* lastPublicKey */mIn.skipInt();
+        mIn.skipInt(); // typeStrings
+        mIn.skipInt(); // lastPublicType
+        mIn.skipInt(); // keyStrings
+        mIn.skipInt(); // lastPublicKey
 
         // TypeIdOffset was added platform_frameworks_base/@f90f2f8dc36e7243b85e0b6a7fd5a590893c827e
         // which is only in split/new applications.
@@ -191,7 +191,7 @@ private void readOverlaySpec() throws AndrolibException, IOException {
 
     private void readOverlayPolicySpec() throws AndrolibException, IOException {
         checkChunkType(Header.XML_TYPE_OVERLAY_POLICY);
-        /* policyFlags */mIn.skipInt();
+        mIn.skipInt(); // policyFlags
         int count = mIn.readInt();
 
         for (int i = 0; i < count; i++) {
@@ -245,7 +245,7 @@ private ResTypeSpec readSingleTableTypeSpec() throws AndrolibException, IOExcept
             mFlagsOffsets.add(new FlagsOffset(mCountIn.getCount(), entryCount));
         }
 
-		/* flags */mIn.skipBytes(entryCount * 4);
+		mIn.skipBytes(entryCount * 4); // flags
         mTypeSpec = new ResTypeSpec(mTypeNames.getString(id - 1), mResTable, mPkg, id, entryCount);
         mPkg.addType(mTypeSpec);
         return mTypeSpec;
@@ -260,7 +260,7 @@ private ResType readTableType() throws IOException, AndrolibException {
         }
 
         int typeFlags = mIn.readByte();
-        /* reserved */mIn.skipBytes(2);
+        mIn.skipBytes(2); // reserved
         int entryCount = mIn.readInt();
         int entriesStart = mIn.readInt();
         mMissingResSpecMap = new LinkedHashMap();
@@ -396,8 +396,8 @@ private ResBagValue readComplexEntry() throws IOException, AndrolibException {
     }
 
     private ResIntBasedValue readValue() throws IOException, AndrolibException {
-		/* size */mIn.skipCheckShort((short) 8);
-		/* zero */mIn.skipCheckByte((byte) 0);
+		mIn.skipCheckShort((short) 8); // size
+		mIn.skipCheckByte((byte) 0); // zero
         byte type = mIn.readByte();
         int data = mIn.readInt();
 
@@ -408,35 +408,61 @@ private ResIntBasedValue readValue() throws IOException, AndrolibException {
 
     private ResConfigFlags readConfigFlags() throws IOException, AndrolibException {
         int size = mIn.readInt();
-        int read = 28;
+        int read = 8;
 
-        if (size < 28) {
-            throw new AndrolibException("Config size < 28");
+        if (size < 8) {
+            throw new AndrolibException("Config size < 8");
         }
 
         boolean isInvalid = false;
 
         short mcc = mIn.readShort();
         short mnc = mIn.readShort();
 
-        char[] language = this.unpackLanguageOrRegion(mIn.readByte(), mIn.readByte(), 'a');
-        char[] country = this.unpackLanguageOrRegion(mIn.readByte(), mIn.readByte(), '0');
+        char[] language = new char[0];
+        char[] country = new char[0];
+        if (size >= 12) {
+            language = this.unpackLanguageOrRegion(mIn.readByte(), mIn.readByte(), 'a');
+            country = this.unpackLanguageOrRegion(mIn.readByte(), mIn.readByte(), '0');
+            read = 12;
+        }
 
-        byte orientation = mIn.readByte();
-        byte touchscreen = mIn.readByte();
+        byte orientation = 0;
+        byte touchscreen = 0;
+        if (size >= 14) {
+            orientation = mIn.readByte();
+            touchscreen = mIn.readByte();
+            read = 14;
+        }
 
-        int density = mIn.readUnsignedShort();
+        int density = 0;
+        if (size >= 16) {
+            density = mIn.readUnsignedShort();
+            read = 16;
+        }
 
-        byte keyboard = mIn.readByte();
-        byte navigation = mIn.readByte();
-        byte inputFlags = mIn.readByte();
-		/* inputPad0 */mIn.skipBytes(1);
+        byte keyboard = 0;
+        byte navigation = 0;
+        byte inputFlags = 0;
+        if (size >= 20) {
+            keyboard = mIn.readByte();
+            navigation = mIn.readByte();
+            inputFlags = mIn.readByte();
+            mIn.skipBytes(1); // inputPad0
+            read = 20;
+        }
 
-        short screenWidth = mIn.readShort();
-        short screenHeight = mIn.readShort();
+        short screenWidth = 0;
+        short screenHeight = 0;
+        short sdkVersion = 0;
+        if (size >= 28) {
+            screenWidth = mIn.readShort();
+            screenHeight = mIn.readShort();
 
-        short sdkVersion = mIn.readShort();
-		/* minorVersion, now must always be 0 */mIn.skipBytes(2);
+            sdkVersion = mIn.readShort();
+            mIn.skipBytes(2); // minorVersion
+            read = 28;
+        }
 
         byte screenLayout = 0;
         byte uiMode = 0;