Test versionbits deployments

src/test/versionbits_tests.cpp

@@ -185,6 +185,28 @@ BOOST_AUTO_TEST_CASE(versionbits_test)
                            .Mine(14333, TestTime(30003), 0).TestActive()
                            .Mine(24000, TestTime(40000), 0).TestActive();
     }
+
+    // Sanity checks of version bit deployments
+    const Consensus::Params &mainnetParams = Params(CBaseChainParams::MAIN).GetConsensus();
+    for (int i=0; i<(int) Consensus::MAX_VERSION_BITS_DEPLOYMENTS; i++) {
+        uint32_t bitmask = VersionBitsMask(mainnetParams, (Consensus::DeploymentPos)i);
+        // Make sure that no deployment tries to set an invalid bit.
+        BOOST_CHECK_EQUAL(bitmask & ~(uint32_t)VERSIONBITS_TOP_MASK, bitmask);
+
+        // Verify that the deployment windows of different deployment using the
+        // same bit are disjoint.
+        // This test may need modification at such time as a new deployment
+        // is proposed that reuses the bit of an activated soft fork, before the
+        // end time of that soft fork.  (Alternatively, the end time of that
+        // activated soft fork could be later changed to be earlier to avoid
+        // overlap.)
+        for (int j=i+1; j<(int) Consensus::MAX_VERSION_BITS_DEPLOYMENTS; j++) {
+            if (VersionBitsMask(mainnetParams, (Consensus::DeploymentPos)j) == bitmask) {
+                BOOST_CHECK(mainnetParams.vDeployments[j].nStartTime > mainnetParams.vDeployments[i].nTimeout ||
+                        mainnetParams.vDeployments[i].nStartTime > mainnetParams.vDeployments[j].nTimeout);
+            }
+        }
+    }
 }
 
 BOOST_AUTO_TEST_CASE(versionbits_computeblockversion)