Allow events to use compact bytes ABI coded data for Solidity 0.4 external events (#891, #992).

packages/abi/src.ts/abi-coder.ts

@@ -83,8 +83,8 @@ export class AbiCoder {
 
     _getWordSize(): number { return 32; }
 
-    _getReader(data: Uint8Array): Reader {
+    _getReader(data: Uint8Array, allowLoose?: boolean): Reader {
-        return new Reader(data, this._getWordSize(), this.coerceFunc);
+        return new Reader(data, this._getWordSize(), this.coerceFunc, allowLoose);
     }
 
     _getWriter(): Writer {
@@ -107,10 +107,10 @@ export class AbiCoder {
         return writer.data;
     }
 
-    decode(types: Array<string | ParamType>, data: BytesLike): Result {
+    decode(types: Array<string | ParamType>, data: BytesLike, loose?: boolean): Result {
         const coders: Array<Coder> = types.map((type) => this._getCoder(ParamType.from(type)));
         const coder = new TupleCoder(coders, "_");
-        return coder.decode(this._getReader(arrayify(data)));
+        return coder.decode(this._getReader(arrayify(data), loose));
     }
 }
 

packages/abi/src.ts/coders/abstract-coder.ts

@@ -131,16 +131,18 @@ export class Writer {
 
 export class Reader {
     readonly wordSize: number;
+    readonly allowLoose: boolean;
 
     readonly _data: Uint8Array;
     readonly _coerceFunc: CoerceFunc;
 
     _offset: number;
 
-    constructor(data: BytesLike, wordSize?: number, coerceFunc?: CoerceFunc) {
+    constructor(data: BytesLike, wordSize?: number, coerceFunc?: CoerceFunc, allowLoose?: boolean) {
         defineReadOnly(this, "_data", arrayify(data));
         defineReadOnly(this, "wordSize", wordSize || 32);
         defineReadOnly(this, "_coerceFunc", coerceFunc);
+        defineReadOnly(this, "allowLoose", allowLoose);
 
         this._offset = 0;
     }
@@ -160,23 +162,27 @@ export class Reader {
         return Reader.coerce(name, value);
     }
 
-    _peekBytes(offset: number, length: number): Uint8Array {
+    _peekBytes(offset: number, length: number, loose?: boolean): Uint8Array {
         let alignedLength = Math.ceil(length / this.wordSize) * this.wordSize;
         if (this._offset + alignedLength > this._data.length) {
+            if (this.allowLoose && loose && this._offset + length <= this._data.length) {
+                alignedLength = length;
+            } else {
                 logger.throwError("data out-of-bounds", Logger.errors.BUFFER_OVERRUN, {
                     length: this._data.length,
                     offset: this._offset + alignedLength
                 });
             }
+        }
         return this._data.slice(this._offset, this._offset + alignedLength)
     }
 
     subReader(offset: number): Reader {
-        return new Reader(this._data.slice(this._offset + offset), this.wordSize, this._coerceFunc);
+        return new Reader(this._data.slice(this._offset + offset), this.wordSize, this._coerceFunc, this.allowLoose);
     }
 
-    readBytes(length: number): Uint8Array {
+    readBytes(length: number, loose?: boolean): Uint8Array {
-        let bytes = this._peekBytes(0, length);
+        let bytes = this._peekBytes(0, length, !!loose);
         this._offset += bytes.length;
         // @TODO: Make sure the length..end bytes are all 0?
         return bytes.slice(0, length);

packages/abi/src.ts/coders/array.ts

@@ -86,9 +86,6 @@ export function unpack(reader: Reader, coders: Array<Coder>): Result {
     // A reader anchored to this base
     let baseReader = reader.subReader(0);
 
-    // The amount of dynamic data read; to consume later to synchronize
-    let dynamicLength = 0;
-
     coders.forEach((coder) => {
         let value: any = null;
 
@@ -105,7 +102,6 @@ export function unpack(reader: Reader, coders: Array<Coder>): Result {
                 value.name = coder.localName;
                 value.type = coder.type;
             }
-            dynamicLength += offsetReader.consumed;
 
         } else {
             try {
@@ -125,10 +121,6 @@ export function unpack(reader: Reader, coders: Array<Coder>): Result {
         }
     });
 
-// @TODO: get rid of this an see if it still works?
-    // Consume the dynamic components in the main reader
-    reader.readBytes(dynamicLength);
-
     // We only output named properties for uniquely named coders
     const uniqueNames = coders.reduce((accum, coder) => {
         const name = coder.localName;

packages/abi/src.ts/coders/bytes.ts

@@ -17,7 +17,7 @@ export class DynamicBytesCoder extends Coder {
     }
 
     decode(reader: Reader): any {
-        return reader.readBytes(reader.readValue().toNumber());
+        return reader.readBytes(reader.readValue().toNumber(), true);
     }
 }
 

packages/abi/src.ts/interface.ts

@@ -475,7 +475,7 @@ export class Interface {
         });
 
         let resultIndexed = (topics != null) ? this._abiCoder.decode(indexed, concat(topics)): null;
-        let resultNonIndexed = this._abiCoder.decode(nonIndexed, data);
+        let resultNonIndexed = this._abiCoder.decode(nonIndexed, data, true);
 
         let result: (Array<any> & { [ key: string ]: any }) = [ ];
         let nonIndexedIndex = 0, indexedIndex = 0;