HellionChat/docs/UPSTREAM_SYNC.md

Upstream Sync

HellionChat is a standalone EUPL-1.2 plugin that originated from Chat 2. Since v1.0.0 it lives under its own namespace, IPC channels and source tree. I no longer track upstream as a Git fork, but I do monitor Chat 2 commits regularly and cherry-pick selectively where it makes sense.

This document covers how that works so anyone (including future-me) can do it cleanly.

A Word on Intent

HellionChat is not trying to replace Chat 2. I build it for myself, and maybe for people who want the same things I do: a privacy-first chat plugin with tighter defaults and no remote-access surface. If that is not you, Chat 2 is the better choice and a well-maintained project.

I am available to Infi if he ever has questions about HellionChat or how I have diverged from the upstream code. What I will not do is interfere with Chat 2's direction or push unsolicited opinions into his project.

Long-term compatibility between Chat 2 and HellionChat is not guaranteed and, frankly, not technically possible. I am building a new UI from scratch and making deliberate architectural decisions that pull in a different direction. Some upstream patches will simply stop applying cleanly and that is expected.

One-Time Setup

Add the upstream repo as a remote on a fresh clone:

git remote add upstream https://github.com/Infiziert90/ChatTwo.git
git fetch upstream

Verify both remotes are wired up:

git remote -v
# origin    https://github.com/JonKazama-Hellion/HellionChat.git (fetch)
# origin    https://github.com/JonKazama-Hellion/HellionChat.git (push)
# upstream  https://github.com/Infiziert90/ChatTwo.git (fetch)
# upstream  https://github.com/Infiziert90/ChatTwo.git (push)

upstream is read-only. Never push to it.

Reviewing What Is New Upstream

Before any feature cycle I run a quick check:

git fetch upstream
git log --oneline main..upstream/main | head -30

That shows every commit Infi or contributors landed since the last sync. I read the messages and decide which ones apply to HellionChat.

What I Cherry-Pick

Always: security fixes, Dalamud API compatibility patches, BetterTTV and emote-cache fixes, regression fixes for upstream behaviour HellionChat still relies on.

Sometimes: small bug fixes in MessageManager.cs, MessageStore.cs, ChatLogWindow.cs, the Tabs system. These come in when they touch code I have not heavily modified.

Never: webinterface changes (the entire webinterface tree is gone in HellionChat), changes that conflict with the privacy filter, changes that re-add upstream defaults I deliberately reversed (full-history logging, Tell Exclusive defaults, etc.).

As HellionChat's UI moves further from the Chat 2 baseline, upstream patches will increasingly require adaptation rather than a clean apply. If a patch cannot be ported without breaking HellionChat behaviour or the privacy model, I skip it rather than force a compromised version in.

How I Cherry-Pick

Always with -x so authorship and the original commit hash stay visible:

git checkout -b sync/upstream-<topic> main
git cherry-pick -x <upstream-commit-sha>

-x appends a (cherry picked from commit <sha>) line to the commit message. That preserves upstream-author credit and lets anyone reading git log trace the change back to Chat 2. Commit messages stay identical to the upstream original; I do not rewrite them to match the HellionChat format.

Conflict Handling

When a cherry-pick conflicts:

1. Resolve by hand. Do not rewrite upstream code to match HellionChat conventions; that is what the merge marker showed.
2. If the conflict is fundamental (touches code that no longer exists in HellionChat), abort the cherry-pick and note why in the relevant GitHub issue or backlog item. Some upstream patches are simply not portable and that is fine.
3. After a clean resolve the commit message stays as-is, with the -x footer Git appends automatically.

Pushing the Sync

Cherry-picked commits go through the same review as any other change. The sync branch lands in main via a no-fast-forward merge, then gets a release tag if user-visible behaviour changed:

git checkout main
git merge --no-ff sync/upstream-<topic> -m "merge: upstream sync — <topic>"

Contributing Back

HellionChat benefits from Chat 2's work, so I try to give something back where I can. If I fix a bug or improve something that would be useful to Chat 2 and is not HellionChat-specific, I submit a good-will PR to Infiziert90/ChatTwo.

A few things to note about that process:

• Good-will PRs are validated in a separate fork first to make sure the fix stands on its own without HellionChat context.
• They are written by hand. No AI-generated code goes to Infi's project. He did not ask for Pair-level AI involvement and I will not push that decision onto his codebase.
• This is not guaranteed for every change, only where it makes sense and where I am confident the fix is clean and self-contained.

When Upstream Goes Silent

If Chat 2 stops receiving updates the remote stays configured and this workflow stays documented. The moment maintenance picks back up I am ready to pull again.

When Upstream Takes a Direction I Cannot Follow

If a future Chat 2 release breaks compatibility with the HellionChat privacy philosophy in a way that cannot be resolved (mandatory cloud sync, removal of the local message store, an incompatible license change), HellionChat continues from the last compatible cherry-pick. The inherited history stays under EUPL-1.2 and stays attributed.