New regression testing for CVE-2018-17144, CVE-2012-2459, and CVE-2010-5137.

CVE-2018-17144 and CVE-2012-2459 are only partially tested for regression.
- CVE-2018-17144 is not tested for the inflation bug.
- CVE-2012-2459 is only tested for the mutated block being rejected, not
for the original block being accepted afterwards.

This commit fixes that limitation.

Also added functional test for CVE-2010-5137.

test/functional/p2p_invalid_block.py

@@ -85,12 +85,13 @@ class InvalidBlockRequestTest(BitcoinTestFramework):
         # Check transactions for duplicate inputs (CVE-2018-17144)
         self.log.info("Test duplicate input block.")
 
-        block2_orig.vtx[2].vin.append(block2_orig.vtx[2].vin[0])
-        block2_orig.vtx[2].rehash()
-        block2_orig.hashMerkleRoot = block2_orig.calc_merkle_root()
-        block2_orig.rehash()
-        block2_orig.solve()
-        node.p2p.send_blocks_and_test([block2_orig], node, success=False, reject_reason='bad-txns-inputs-duplicate')
+        block2_dup = copy.deepcopy(block2_orig)
+        block2_dup.vtx[2].vin.append(block2_dup.vtx[2].vin[0])
+        block2_dup.vtx[2].rehash()
+        block2_dup.hashMerkleRoot = block2_dup.calc_merkle_root()
+        block2_dup.rehash()
+        block2_dup.solve()
+        node.p2p.send_blocks_and_test([block2_dup], node, success=False, reject_reason='bad-txns-inputs-duplicate')
 
         self.log.info("Test very broken block.")
 
@@ -106,5 +107,31 @@ class InvalidBlockRequestTest(BitcoinTestFramework):
         node.p2p.send_blocks_and_test([block3], node, success=False, reject_reason='bad-cb-amount')
 
 
+        # Complete testing of CVE-2012-2459 by sending the original block.
+        # It should be accepted even though it has the same hash as the mutated one.
+
+        self.log.info("Test accepting original block after rejecting its mutated version.")
+        node.p2p.send_blocks_and_test([block2_orig], node, success=True, timeout=5)
+
+        # Update tip info
+        height += 1
+        block_time += 1
+        tip = int(block2_orig.hash, 16)
+
+        # Complete testing of CVE-2018-17144, by checking for the inflation bug.
+        # Create a block that spends the output of a tx in a previous block.
+        block4 = create_block(tip, create_coinbase(height), block_time)
+        tx3 = create_tx_with_script(tx2, 0, script_sig=b'\x51', amount=50 * COIN)
+
+        # Duplicates input
+        tx3.vin.append(tx3.vin[0])
+        tx3.rehash()
+        block4.vtx.append(tx3)
+        block4.hashMerkleRoot = block4.calc_merkle_root()
+        block4.rehash()
+        block4.solve()
+        self.log.info("Test inflation by duplicating input")
+        node.p2p.send_blocks_and_test([block4], node, success=False,  reject_reason='bad-txns-inputs-duplicate')
+
 if __name__ == '__main__':
     InvalidBlockRequestTest().main()