From 7b90059a42c6562c00bb7ed0422dbac1ea48c86b Mon Sep 17 00:00:00 2001
From: janko33bd <janko33bd@gmail.com>
Date: Wed, 13 Dec 2017 00:27:05 +0100
Subject: [PATCH]  make 0 value data outputs standard

---
 src/policy/policy.cpp |  8 ++++++++
 src/script/script.cpp | 27 +++++++++++++++++++++++++++
 src/script/script.h   |  1 +
 3 files changed, 36 insertions(+)

diff --git a/src/policy/policy.cpp b/src/policy/policy.cpp
index 805eaedc3..6a5750584 100644
--- a/src/policy/policy.cpp
+++ b/src/policy/policy.cpp
@@ -111,6 +111,14 @@ bool IsStandardTx(const CTransaction& tx, std::string& reason)
 
         if (whichType == TX_NULL_DATA)
             nDataOut++;
+        else if (txout.nValue == 0) {
+        	reason = "dust";
+            return false;
+        }
+        if (!txout.scriptPubKey.HasCanonicalPushes()) {
+            reason = "scriptpubkey-non-canonical-push";
+            return false;
+        }
         else if ((whichType == TX_MULTISIG) && (!fIsBareMultisigStd)) {
             reason = "bare-multisig";
             return false;
diff --git a/src/script/script.cpp b/src/script/script.cpp
index 3b622a4e9..e684b4e47 100644
--- a/src/script/script.cpp
+++ b/src/script/script.cpp
@@ -252,3 +252,30 @@ bool CScript::IsPushOnly() const
 {
     return this->IsPushOnly(begin());
 }
+
+bool CScript::HasCanonicalPushes() const
+{
+    const_iterator pc = begin();
+    while (pc < end())
+    {
+        opcodetype opcode;
+        std::vector<unsigned char> data;
+        if (!GetOp(pc, opcode, data))
+            return false;
+        if (opcode > OP_16)
+            continue;
+        if (opcode < OP_PUSHDATA1 && opcode > OP_0 && (data.size() == 1 && data[0] <= 16))
+            // Could have used an OP_n code, rather than a 1-byte push.
+            return false;
+        if (opcode == OP_PUSHDATA1 && data.size() < OP_PUSHDATA1)
+            // Could have used a normal n-byte push, rather than OP_PUSHDATA1.
+            return false;
+        if (opcode == OP_PUSHDATA2 && data.size() <= 0xFF)
+            // Could have used an OP_PUSHDATA1.
+            return false;
+        if (opcode == OP_PUSHDATA4 && data.size() <= 0xFFFF)
+            // Could have used an OP_PUSHDATA2.
+            return false;
+    }
+    return true;
+}
diff --git a/src/script/script.h b/src/script/script.h
index 40feb906f..4d84276f5 100644
--- a/src/script/script.h
+++ b/src/script/script.h
@@ -617,6 +617,7 @@ public:
     /** Called by IsStandardTx and P2SH/BIP62 VerifyScript (which makes it consensus-critical). */
     bool IsPushOnly(const_iterator pc) const;
     bool IsPushOnly() const;
+    bool HasCanonicalPushes() const;
 
     bool IsUnspendable() const
     {