Allow 0 ResourceTableChunks and TypeSpecChunk to be null

java/com/google/devrel/gmscore/tools/apk/arsc/PackageChunk.java

@@ -197,9 +197,15 @@ public Collection<TypeSpecChunk> getTypeSpecChunks() {
     return typeSpecs.values();
   }
 
-  /** For a given (1-based) type id, returns the {@link TypeSpecChunk} matching it. */
+  /**
+   * For a given (1-based) type id, returns the {@link TypeSpecChunk} matching it.
+   */
   public TypeSpecChunk getTypeSpecChunk(int id) {
-    return Preconditions.checkNotNull(typeSpecs.get(id));
+    if (typeSpecs.containsKey(id)) {
+      return typeSpecs.get(id);
+    } else {
+      return null;
+    }
   }
 
   /**

java/com/google/devrel/gmscore/tools/apk/arsc/ResourceEntryStatsCollector.java

@@ -174,7 +174,9 @@ private void computeTypeSpecSizes(PackageChunk packageChunk,
       // The 1 here is to convert back to a 1-based index.
       TypeSpecChunk typeSpec = packageChunk.getTypeSpecChunk(i + 1);
       // TypeSpecChunk entries share everything equally.
-      addSizes(usages[i], typeSpec.getOriginalChunkSize(), 0, 1);
+      if (typeSpec != null) {
+        addSizes(usages[i], typeSpec.getOriginalChunkSize(), 0, 1);
+      }
     }
   }
 

java/com/google/devrel/gmscore/tools/apk/arsc/ResourceTableChunk.java

@@ -49,7 +49,7 @@ public class ResourceTableChunk extends ChunkWithChunks {
   protected ResourceTableChunk(ByteBuffer buffer, @Nullable Chunk parent) {
     super(buffer, parent);
     // packageCount. We ignore this, because we already know how many chunks we have.
-    Preconditions.checkState(buffer.getInt() >= 1, "ResourceTableChunk package count was < 1.");
+    Preconditions.checkState(buffer.getInt() >= 0, "ResourceTableChunk package count was < 0.");
   }
 
   @Override