From 9f5f973d8a41b3f97157939d38479d17b884ce21 Mon Sep 17 00:00:00 2001
From: Nicola Atzei <atzeinicola@gmail.com>
Date: Thu, 26 Oct 2017 15:20:06 +0200
Subject: [PATCH] ScriptBuilder: Fix minimal number encoding for -1.

---
 .../org/bitcoinj/script/ScriptBuilder.java    | 10 +++---
 .../bitcoinj/script/ScriptBuilderTest.java    | 34 +++++++++++++++++++
 2 files changed, 38 insertions(+), 6 deletions(-)
 create mode 100644 core/src/test/java/org/bitcoinj/script/ScriptBuilderTest.java

diff --git a/core/src/main/java/org/bitcoinj/script/ScriptBuilder.java b/core/src/main/java/org/bitcoinj/script/ScriptBuilder.java
index 1d114c56..abe5d586 100644
--- a/core/src/main/java/org/bitcoinj/script/ScriptBuilder.java
+++ b/core/src/main/java/org/bitcoinj/script/ScriptBuilder.java
@@ -112,11 +112,7 @@ public class ScriptBuilder {
      * shortest encoding possible.
      */
     public ScriptBuilder number(long num) {
-        if (num >= 0 && num <= 16) {
-            return smallNum((int) num);
-        } else {
-            return bigNum(num);
-        }
+        return number(chunks.size(), num);
     }
 
     /**
@@ -124,7 +120,9 @@ public class ScriptBuilder {
      * uses shortest encoding possible.
      */
     public ScriptBuilder number(int index, long num) {
-        if (num >= 0 && num <= 16) {
+        if (num == -1) {
+            return op(index, OP_1NEGATE);
+        } else if (num >= 0 && num <= 16) {
             return smallNum(index, (int) num);
         } else {
             return bigNum(index, num);
diff --git a/core/src/test/java/org/bitcoinj/script/ScriptBuilderTest.java b/core/src/test/java/org/bitcoinj/script/ScriptBuilderTest.java
new file mode 100644
index 00000000..6721e4e5
--- /dev/null
+++ b/core/src/test/java/org/bitcoinj/script/ScriptBuilderTest.java
@@ -0,0 +1,34 @@
+/*
+ * Copyright 2017 Nicola Atzei
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.bitcoinj.script;
+
+import static org.junit.Assert.assertTrue;
+
+import org.junit.Test;
+
+public class ScriptBuilderTest {
+
+    @Test
+    public void testNumber() {
+        for (int i = -100; i <= 100; i++) {
+            Script s = new ScriptBuilder().number(i).build();
+            for (ScriptChunk ch : s.chunks) {
+                assertTrue(Integer.toString(i), ch.isShortestPossiblePushData());
+            }
+        }
+    }
+}