RPC getblocktemplate returns version: -1476395008

[nickoarg]

Describe the issue

Pool receives an incorrect version data in the rpc response for getworktemplate

Can you reliably reproduce the issue?

Yes

If so, please list the steps to reproduce below:

1. Compile in linux, ubuntu 16.04
2. run meritd --daemon
3. curl --user rpcpool --data-binary '{"jsonrpc":"1.0", "method" : "getblocktemplate","params" : [{"capabilities" : ["coinbasetxn","workid","coinbase/append"]}],"id" : 2}' -H 'content-type: text/plain;' http://127.0.0.1:8332/

get:
Enter host password for user 'rpcpool':
{"result":{"capabilities":["proposal"],"version":-1476395008,"previousblockhash": ...

Expected behaviour

Version should be valid System.UInt32

Actual behaviour

meritd returned an invalid value

Screenshots.

What version of merit-core are you using?

Self compiled from source

Machine specs:

• OS: ubuntu 16.04
• CPU: 2
• RAM: 16gb
• Disk size: 55gb
• Disk Type (HD/SDD): nvme

[nickoarg]

merit/src/rpc/mining.cpp

Line 714 in da2c144

result.push_back(Pair("version", pblock->nVersion));

Removed that line, recomiled and it works.

[tonypizzicato]

@nickoarg what's your gcc version?

[tonypizzicato]

can you try to replace this line with
result.push_back(Pair("version", static_cast<uint64_t>(pblock->nVersion)));
and paste returned block version here?

[barrystyle]

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>

int main()
{
        uint32_t versionBits = -1476395008;
        printf("%08x \n", versionBits);

        return(0);
}

a8000000

while not conventional, the version is just fine..

[nickoarg]

Hi Tony,

$ gcc --version
gcc (Ubuntu 5.4.0-6ubuntu1~16.04.10) 5.4.0 20160609
Copyright (C) 2015 Free Software Foundation, Inc.

And the returned bloc after modifying with the suggested change:
System.Exception: There was a problem deserializing the response from the coin wallet. ---> Newtonsoft.Json.JsonSerializationException: Error converting value 18446744072233156608 to type 'System.UInt32'. Path 'result.version', line 6, position 35. ---> System.InvalidOperationException: Can not convert from BigInteger to System.UInt32. ---> System.OverflowException: Value was either too large or too small for an Int64.

[barrystyle]

System.Exception: There was a problem deserializing the response from the coin wallet. ---> Newtonsoft.Json.JsonSerializationException: Error converting value 18446744072233156608 to type 'System.UInt32'. Path 'result.version', line 6, position 35. ---> System.InvalidOperationException: Can not convert from BigInteger to System.UInt32. ---> System.OverflowException: Value was either too large or too small for an Int64.

thats not an issue with gcc, thats from .net, where are you seeing this?

[nickoarg]

At the pool software. Yes, is the .net that is complaining.
But the json Object deserializator is external, so I beleive that the merit node is returning an unexpected value.

[tonypizzicato]

looks like a quick fix can be
result.push_back(Pair("version", strprintf("%u", pblock->nVersion)));
we need to figure out why this is happening though

[nickoarg]

System.Exception: There was a problem deserializing the response from the coin wallet. ---> Newtonsoft.Json.JsonSerializationException: Error converting value "-1476395008" to type 'System.UInt32'. Path 'result.version', line 7, position 28. ---> System.OverflowException: Value was either too large or too small for a UInt32.
  at System.Number.ParseUInt32 (System.String value, System.Globalization.NumberStyles options, System.Globalization.NumberFormatInfo numfmt) <0x7f9edd1eab70 + 0x0013a> in <2943701620b54f86b436d3ffad010412>:0

I'm still getting this error

    //result.push_back(Pair("version", pblock->nVersion));
    result.push_back(Pair("previousblockhash", pblock->hashPrevBlock.GetHex()));
    result.push_back(Pair("version", strprintf("%u", pblock->nVersion)));

[barrystyle]

@nickoarg bonesoul/CoiniumServ#933 shows a similar issue where it overflows a uint32/64 using dotnet, might provide some clues?

i can speak authoritatively here and say icemining (the first non-dev pool) interprets the version -1476395008 as versionbits a8000000, with no issues on submitblock, nor warnings like unknown block versions are being mined, which I have recently observed in the past few days.

interpreting version as a uint32 should return 2818572288, then as hex a8000000.

not a great solution, but try:
result.push_back(Pair("version", strprintf("%u", 2818572288)));

[nickoarg]

I've updated the node to 0.6.4 and the issue persists. I'll see if I can use bonesoul/CoiniumServ#933

[barrystyle]

@nickoarg try this:
barrystyle@e6f5794

have submitted PR to merits team

[nickoarg]

Just tried that. Same result:

21:06:17 [Fatal] [Program] [global] Terminating because of unhandled exception!
System.Exception: There was a problem deserializing the response from the coin wallet. ---> Newtonsoft.Json.JsonSerializationException: Error converting value -1476395008 to type 'System.UInt32'. Path 'result.version', line 6, position 26. ---> System.OverflowException: Value was either too large or too small for a UInt32.
  at System.Int64.System.IConvertible.ToUInt32 (System.IFormatProvider provider) <0x7f0bf51e6680 + 0x0002d> in <2943701620b54f86b436d3ffad010412>:0
  at System.Convert.ChangeType (System.Object value, System.Type conversionType, System.IFormatProvider provider) <0x7f0bf51bbe60 + 0x0028d> in <2943701620b54f86b436d3ffad010412>:0
  at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.EnsureType (Newtonsoft.Json.JsonReader reader, System.Object value, System.Globalization.CultureInfo culture, Newtonsoft.Json.Serialization.JsonContract contract, System.Type targetType) [0x000c0] in <b1d2c1d6f4dd47bea2964bdd6464f67d>:0

Running over Mono 5.14.0.177 (tarball Mon Aug 6 09:13:43 UTC 2018), framework: 4.5 (v4.0.30319.42000).

[barrystyle]

its still displaying -1476395008?
do you want to doublecheck & compile again?

the build displays that number on my machine pre-patch.. the patch gives 671088640 as a result