scripts: fix isScriptHashInput classification

src/scripts.js

@@ -73,15 +73,12 @@ function isScriptHashInput (script, allowIncomplete) {
   if (!Buffer.isBuffer(lastChunk)) return false
 
   var scriptSig = Script.fromChunks(script.chunks.slice(0, -1))
-  var scriptPubKey
+  var redeemScript = Script.fromBuffer(lastChunk)
 
-  try {
-    scriptPubKey = Script.fromBuffer(lastChunk)
-  } catch (e) {
-    return false
-  }
+  // is redeemScript a valid script?
+  if (redeemScript.chunks.length === 0) return false
 
-  return classifyInput(scriptSig, allowIncomplete) === classifyOutput(scriptPubKey)
+  return classifyInput(scriptSig, allowIncomplete) === classifyOutput(redeemScript)
 }
 
 function isScriptHashOutput (script) {

test/fixtures/scripts.json

@@ -113,7 +113,7 @@
         "scriptSig": "OP_0 304402207515cf147d201f411092e6be5a64a6006f9308fad7b2a8fdaab22cd86ce764c202200974b8aca7bf51dbf54150d3884e1ae04f675637b926ec33bf75939446f6ca2801 3045022100ef253c1faa39e65115872519e5f0a33bbecf430c0f35cf562beabbad4da24d8d02201742be8ee49812a73adea3007c9641ce6725c32cd44ddb8e3a3af460015d140501 OP_RESERVED"
       },
       {
-        "description": "signature forms invalid script",
+        "description": "redeemScript is a signature, therefore not a valid script",
         "scriptSig": "OP_0 3045022100e12b17b3a4c80c401a1687487bd2bafee9e5f1f8f1ffc6180ce186672ad7b43a02205e316d1e5e71822f5ef301b694e578fa9c94af4f5f098c952c833f4691307f4e01"
       }
     ],

test/scripts.js

@@ -86,7 +86,7 @@ describe('Scripts', function () {
 
       fixtures.invalid[inputFnName].forEach(function (f) {
         if (inputFn && f.scriptSig) {
-          it('returns false for ' + f.scriptSig, function () {
+          it('returns false for ' + f.description + ' (' + f.scriptSig + ')', function () {
             var script = Script.fromASM(f.scriptSig)
 
             assert.equal(inputFn(script), false)
@@ -112,7 +112,7 @@ describe('Scripts', function () {
 
       fixtures.invalid[outputFnName].forEach(function (f) {
         if (outputFn && f.scriptPubKey) {
-          it('returns false for ' + f.scriptPubKey, function () {
+          it('returns false for ' + f.description + ' (' + f.scriptPubKey + ')', function () {
             var script = Script.fromASM(f.scriptPubKey)
 
             assert.equal(outputFn(script), false)