renepay crashes after retrying an xpay payment

[Lagrang3]

Trying a payment with xpay version v24.11.1, I noticed the groupid is a huge number.
I am not sure this is expected but it is beyond u32. It seems like uninitialized values to me.

For example

cln listsendpays
...
      {
         "created_index": 1068,
         "id": 1068,
         "payment_hash": "efa0ffd0c279c3d0586c06a4d53b633dcee23c66205c5bbb1407e9f0301f843e",
         "groupid": 3129650225004885374,
         "updated_index": 1068,
         "partid": 3,
         "destination": "03d607f3e69fd032524a867b288216bfab263b6eaee4e07783799a6fe69bb84fac",
         "amount_msat": 20405000,
         "amount_sent_msat": 20437609,
         "created_at": 1735062389,
         "completed_at": 1735062391,
         "status": "failed",
         "bolt11": "lnbc204050n1pnk4umfpp5a7s0l5xz08paqkrvq6jd2wmr8h8wy0rxypw9hwc5ql5lqvqlsslqdz2gf5hgun9ve5kcmpqxc6xvve48ycnzttr89sk2tf5vvungtfcvgmrzttyvyurgvfkxgckgcnrxucqzx7xqrpcgsp597v4m0mpn2w2scqdsq0tuj4r4qslqzyqs7qw3q3mgcw3057qwjds9qxpqysgqg69v0q6q7gpxz9r2l5ufpd6yl2eszf2xa6483spx6m68hwekzg4kesanmuvqmrm2qj5s2mz7zvsa8vmdfdvtvdareu88qdqkz9jntrgpu56kqy",
         "erroronion": "c921aef47f8a4bc12e1f3a5a39f6becc16e94dbffc48517c90d67744570ed386b08dac56d7744a52e99023459bfce6e0fb4f6e24238cf88b2f8c77d2c14dac949bf098c07f9c4ad8f112e0c911c755f85f08885710c2dea5caf19e5f5adda2771dfd880581b42f87a05bf7e65473c6bf53a4386ce0071ce1c1f65b561d1a90217e58ca48fdc2a7b840cf2e008282f65ca437c36341492421f03c6f37c24e0395dfb82874c2d8db11624f11dd4769c6ac610c8bc1257f342bdaf7b6ab7c44517a8fd98c666e048a01570c13aa681bbe172b0829355414948fcc232cc0e1666bbd740827687245c690385a7bd5af1ad9ac6658254c76abc4ee4ff993de8175a671daec4c51d2e62627aaf701444bc35f41c573e94a9e5a77792a3ee8749bb26f1bdbbc3fa2"
      },
      {
         "created_index": 1069,
         "id": 1069,
         "payment_hash": "efa0ffd0c279c3d0586c06a4d53b633dcee23c66205c5bbb1407e9f0301f843e",
         "groupid": 3129650225004885374,
         "updated_index": 1069,
         "partid": 4,
         "destination": "03d607f3e69fd032524a867b288216bfab263b6eaee4e07783799a6fe69bb84fac",
         "amount_msat": 20405000,
         "amount_sent_msat": 20432556,
         "created_at": 1735062391,
         "completed_at": 1735062394,
         "status": "complete",
         "payment_preimage": "xxx",
         "bolt11": "lnbc204050n1pnk4umfpp5a7s0l5xz08paqkrvq6jd2wmr8h8wy0rxypw9hwc5ql5lqvqlsslqdz2gf5hgun9ve5kcmpqxc6xvve48ycnzttr89sk2tf5vvungtfcvgmrzttyvyurgvfkxgckgcnrxucqzx7xqrpcgsp597v4m0mpn2w2scqdsq0tuj4r4qslqzyqs7qw3q3mgcw3057qwjds9qxpqysgqg69v0q6q7gpxz9r2l5ufpd6yl2eszf2xa6483spx6m68hwekzg4kesanmuvqmrm2qj5s2mz7zvsa8vmdfdvtvdareu88qdqkz9jntrgpu56kqy"
      }
   ]

[whitslack]

If one tries renepay on the same invoice after xpay fails, then the cln-renepay plugin crashes with:

2025-01-06T19:06:04.898Z **BROKEN** plugin-cln-renepay: pendingsendpays_done json_scan of listsendpay returns the following error: Parsing '{status:%,groupid:%': json_to_u32 could not parse 6052863309857293674
2025-01-06T19:06:04.906Z INFO    plugin-cln-renepay: Killing plugin: exited during normal operation

[Lagrang3]

Allright, so xpay sets the group id as a random number. That explains it.

payment->group_id = pseudorand(INT64_MAX);

On the other hand renepay expects group ids as 32 bit integers.
I'll fix renepay to read group ids as 64 bit integers.

[lightningcheckout]

Nice, I ran into this issue as well. Since xpay more often fails due to #7960