Make fork warning use version bit masking, on the assumption that fro…

…m this point on all changes will be triggered by a bit in nVersion rather than an incrementing integer.
jtoomim · Dec 3, 2015 · 463db05 · 463db05
1 parent fadcd7d
commit 463db05
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Showing 3 changed files with 20 additions and 4 deletions.
diff --git a/qa/rpc-tests/forknotify.py b/qa/rpc-tests/forknotify.py
@@ -22,16 +22,29 @@ def setup_network(self):
         with open(self.alert_filename, 'w') as f:
             pass  # Just open then close to create zero-length file
         self.nodes.append(start_node(0, self.options.tmpdir,
-                            ["-blockversion=2", "-alertnotify=echo %s >> \"" + self.alert_filename + "\""]))
+                            ["-blockversion=3", "-alertnotify=echo %s >> \"" + self.alert_filename + "\""]))
         # Node1 mines block.version=211 blocks
         self.nodes.append(start_node(1, self.options.tmpdir,
                                 ["-blockversion=211"]))
         connect_nodes(self.nodes[1], 0)
 
+        # Node2 mines block.version=0x20000007 blocks
+        self.nodes.append(start_node(2, self.options.tmpdir,
+                            ["-blockversion=%d"%(0x20000007,)]))
+        connect_nodes(self.nodes[2], 0)
+
         self.is_network_split = False
         self.sync_all()
 
     def run_test(self):
+        # Should be no alerts if nodes 0 or 2 mine:
+        self.nodes[0].generate(1)
+        self.sync_all()
+        self.nodes[2].generate(1)
+        self.sync_all()
+        if os.stat(self.alert_filename).st_size > 0:
+            raise AssertionError("Erroneous up-version alert")
+
         # Mine 51 up-version blocks
         self.nodes[1].generate(51)
         self.sync_all()

diff --git a/src/main.cpp b/src/main.cpp
@@ -2230,12 +2230,12 @@ void static UpdateTip(CBlockIndex *pindexNew) {
         const CBlockIndex* pindex = chainActive.Tip();
         for (int i = 0; i < 100 && pindex != NULL; i++)
         {
-            if (pindex->nVersion > CBlock::CURRENT_VERSION)
+            if ((pindex->nVersion & ~CBlock::UNDERSTOOD_VERSIONS) != 0)
                 ++nUpgraded;
             pindex = pindex->pprev;
         }
         if (nUpgraded > 0)
-            LogPrintf("%s: %d of last 100 blocks above version %d\n", __func__, nUpgraded, (int)CBlock::CURRENT_VERSION);
+            LogPrintf("%s: %d of last 100 blocks contain unknown version feature bit\n", __func__, nUpgraded);
         if (nUpgraded > 100/2)
         {
             // strMiscWarning is read by GetWarnings(), called by Qt and the JSON-RPC code to warn the user:

diff --git a/src/primitives/block.h b/src/primitives/block.h
@@ -23,8 +23,11 @@ const unsigned int SIZE_FORK_VERSION = 0x20000007;
 class CBlockHeader
 {
 public:
-    // header
     static const int32_t CURRENT_VERSION=SIZE_FORK_VERSION;
+    // This code knows the rules for these block versions:
+    static const int32_t UNDERSTOOD_VERSIONS = (SIZE_FORK_VERSION | 3 | 2 | 1);
+
+    // header
     int32_t nVersion;
     uint256 hashPrevBlock;
     uint256 hashMerkleRoot;