Merge #9619: Bugfix: RPC/Mining: GBT should return 1 MB sizelimit before segwit activates

279f944 QA: Test GBT size/weight limit values (Luke Dashjr)
9fc7f0b Bugfix: RPC/Mining: GBT should return 1 MB sizelimit before segwit activates (Luke Dashjr)

Author: laanwj

qa/rpc-tests/segwit.py

@@ -130,10 +130,14 @@ def run_test(self):
         print("Verify sigops are counted in GBT with pre-BIP141 rules before the fork")
         txid = self.nodes[0].sendtoaddress(self.nodes[0].getnewaddress(), 1)
         tmpl = self.nodes[0].getblocktemplate({})
+        assert(tmpl['sizelimit'] == 1000000)
+        assert('weightlimit' not in tmpl)
         assert(tmpl['sigoplimit'] == 20000)
         assert(tmpl['transactions'][0]['hash'] == txid)
         assert(tmpl['transactions'][0]['sigops'] == 2)
         tmpl = self.nodes[0].getblocktemplate({'rules':['segwit']})
+        assert(tmpl['sizelimit'] == 1000000)
+        assert('weightlimit' not in tmpl)
         assert(tmpl['sigoplimit'] == 20000)
         assert(tmpl['transactions'][0]['hash'] == txid)
         assert(tmpl['transactions'][0]['sigops'] == 2)
@@ -241,6 +245,8 @@ def run_test(self):
         print("Verify sigops are counted in GBT with BIP141 rules after the fork")
         txid = self.nodes[0].sendtoaddress(self.nodes[0].getnewaddress(), 1)
         tmpl = self.nodes[0].getblocktemplate({'rules':['segwit']})
+        assert(tmpl['sizelimit'] >= 3999577)  # actual maximum size is lower due to minimum mandatory non-witness data
+        assert(tmpl['weightlimit'] == 4000000)
         assert(tmpl['sigoplimit'] == 80000)
         assert(tmpl['transactions'][0]['txid'] == txid)
         assert(tmpl['transactions'][0]['sigops'] == 8)
@@ -250,6 +256,8 @@ def run_test(self):
         try:
             tmpl = self.nodes[0].getblocktemplate({})
             assert(len(tmpl['transactions']) == 1)  # Doesn't include witness tx
+            assert(tmpl['sizelimit'] == 1000000)
+            assert('weightlimit' not in tmpl)
             assert(tmpl['sigoplimit'] == 20000)
             assert(tmpl['transactions'][0]['hash'] == txid)
             assert(tmpl['transactions'][0]['sigops'] == 2)

src/rpc/mining.cpp

@@ -676,8 +676,12 @@ UniValue getblocktemplate(const JSONRPCRequest& request)
         nSigOpLimit /= WITNESS_SCALE_FACTOR;
     }
     result.push_back(Pair("sigoplimit", nSigOpLimit));
-    result.push_back(Pair("sizelimit", (int64_t)MAX_BLOCK_SERIALIZED_SIZE));
-    result.push_back(Pair("weightlimit", (int64_t)MAX_BLOCK_WEIGHT));
+    if (fPreSegWit) {
+        result.push_back(Pair("sizelimit", (int64_t)MAX_BLOCK_BASE_SIZE));
+    } else {
+        result.push_back(Pair("sizelimit", (int64_t)MAX_BLOCK_SERIALIZED_SIZE));
+        result.push_back(Pair("weightlimit", (int64_t)MAX_BLOCK_WEIGHT));
+    }
     result.push_back(Pair("curtime", pblock->GetBlockTime()));
     result.push_back(Pair("bits", strprintf("%08x", pblock->nBits)));
     result.push_back(Pair("height", (int64_t)(pindexPrev->nHeight+1)));