From eeeff1f7951362ce7745bf932165d605a7424efc Mon Sep 17 00:00:00 2001
From: Christopher Jeffrey <chjjeffrey@gmail.com>
Date: Mon, 6 Mar 2017 18:03:56 -0800
Subject: [PATCH] chain: skip all preliminary verification when using
 checkpoints.

---
 lib/blockchain/chain.js | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/lib/blockchain/chain.js b/lib/blockchain/chain.js
index 49fe3e2f..6b44757f 100644
--- a/lib/blockchain/chain.js
+++ b/lib/blockchain/chain.js
@@ -231,9 +231,26 @@ Chain.prototype.verify = co(function* verify(block, prev, flags) {
 
   assert(typeof flags === 'number');
 
+  // Extra sanity check.
   if (block.prevBlock !== prev.hash)
     throw new VerifyError(block, 'invalid', 'bad-prevblk', 0);
 
+  // Skip everything when using checkpoints.
+  // We can do this safely because every
+  // block in between each checkpoint was
+  // validated outside in the header chain.
+  if (prev.isHistorical()) {
+    if (this.options.spv)
+      return new DeploymentState();
+
+    // Once segwit is active, we will still
+    // need to check for block mutability.
+    if (!block.hasWitness() && !block.getCommitmentHash())
+      return new DeploymentState();
+
+    flags &= ~common.flags.VERIFY_BODY;
+  }
+
   // Non-contextual checks.
   if (flags & common.flags.VERIFY_BODY) {
     if (!block.verifyBody(ret)) {