From 2afbf25e25befddd0f659c12111488ef4b3312d9 Mon Sep 17 00:00:00 2001
From: laanwj <126646+laanwj@users.noreply.github.com>
Date: Thu, 26 May 2022 20:06:07 +0200
Subject: [PATCH] Merge bitcoin/bitcoin#24032: Add defaults to vDeployments to
 avoid uninitialized variables

c4c5b9ca6e98cf44309af73edf5559940a04d00f consensus/params: set default values for BIP9Deployment (Anthony Towns)

Pull request description:

  Adds default values for `vDeployments` in `consensus/params.h` so that undefined behaviour is avoided if a deployment is not initialized. Also adds a check in the unit tests to alert if this is happening, since even if it doesn't invoke undefined behaviour it's probably a mistake.

ACKs for top commit:
  laanwj:
    Code review ACK c4c5b9ca6e98cf44309af73edf5559940a04d00f

Tree-SHA512: 22d7ff86a817d9e9e67c47301fc3b7e9d5821c13565d7706711f113dea220eea29b413a7c8d029691009159cebc85a108d77cb52418734091c196bafb2b12423
---
 src/consensus/params.h         | 6 +++---
 src/test/versionbits_tests.cpp | 1 +
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/src/consensus/params.h b/src/consensus/params.h
index 7d6e9772c2751..f025d8a54034c 100644
--- a/src/consensus/params.h
+++ b/src/consensus/params.h
@@ -46,11 +46,11 @@ constexpr bool ValidDeployment(DeploymentPos dep) { return DEPLOYMENT_TESTDUMMY
  */
 struct BIP9Deployment {
     /** Bit position to select the particular bit in nVersion. */
-    int bit;
+    int bit{28};
     /** Start MedianTime for version bits miner confirmation. Can be a date in the past */
-    int64_t nStartTime;
+    int64_t nStartTime{NEVER_ACTIVE};
     /** Timeout/expiry MedianTime for the deployment attempt. */
-    int64_t nTimeout;
+    int64_t nTimeout{NEVER_ACTIVE};
     /** If lock in occurs, delay activation until at least this block
      *  height.  Note that activation will only occur on a retarget
      *  boundary.
diff --git a/src/test/versionbits_tests.cpp b/src/test/versionbits_tests.cpp
index af31496fc5d82..0695e33a32133 100644
--- a/src/test/versionbits_tests.cpp
+++ b/src/test/versionbits_tests.cpp
@@ -282,6 +282,7 @@ static void check_computeblockversion(const Consensus::Params& params, Consensus
         nStartTime == Consensus::BIP9Deployment::NEVER_ACTIVE)
     {
         BOOST_CHECK_EQUAL(min_activation_height, 0);
+        BOOST_CHECK_EQUAL(nTimeout, Consensus::BIP9Deployment::NO_TIMEOUT);
         return;
     }