Merge pull request bitcoin#3 from 0xBEEFCAF3/cat

Update OP_CAT implementation code

Author: EthanHeilman

bip-???-cat.mediawiki

@@ -43,18 +43,15 @@ OP_CAT pops two elements off the stack, concatenates them together in stack orde
 
 ===Implementation===
 <pre>
-case OP_CAT:
-{
-    if (stack.size() < 2) {
-        return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
-    }
-    valtype& vch1 = stacktop(-2);
-    valtype& vch2 = stacktop(-1);
-    if (vch1.size() + vch2.size() > MAX_SCRIPT_ELEMENT_SIZE) {
-        return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
-    }
-    vch1.insert(vch1.end(), vch2.begin(), vch2.end());
-    stack.pop_back();
+case OP_CAT: {
+  if (stack.size() < 2)
+    return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
+  valtype& vch1 = stacktop(-2);
+  valtype& vch2 = stacktop(-1);
+  if (vch1.size() + vch2.size() > MAX_SCRIPT_ELEMENT_SIZE)
+    return set_error(serror, SCRIPT_ERR_PUSH_SIZE);
+  vch1.insert(vch1.end(), vch2.begin(), vch2.end());
+  stack.pop_back();
 }
 break;
 </pre>