CreatePullRequest never updates an existing PR on Gitea/Forgejo: `head` filter uses GitHub's `owner:branch` format, causing a 409 on every run after the first

[JonBasse]

Summary

On the Gitea/Forgejo backend, CreatePullRequest can never find an existing pull request, so its documented update path is unreachable. From the second run onward it always attempts a create and the forge answers HTTP 409.

The docs state:

Create a pull request on every configured forge from the current branch to a specified branch. If a pull request for those already exists, this step will overwrite the title and body of the existing pull request.

The code intends exactly that — the function is create_or_update_pull_request — but on Gitea/Forgejo the lookup always returns zero rows, so the else (create) branch is always taken.

Cause

crates/knope/src/integrations/gitea/create_pull_request.rs builds the lookup query using GitHub's cross-repo owner:branch convention:

.query(&[
    ("state", "open"),
    (
        "head",
        &format!("{owner}:{current_branch}", owner = config.owner),
    ),
    ("base", base),
    ("access_token", &token),
])

Gitea/Forgejo's list endpoint does not use that convention. GET /repos/{owner}/{repo}/pulls documents head as "Filter by head branch name" and passes the raw string straight through — routers/api/v1/repo/pull.go:

BaseBranch:  ctx.FormTrim("base"),
HeadBranch:  ctx.FormTrim("head"),

which is then matched by exact SQL equality — models/issues/pull_list.go:

if opts.HeadBranch != "" {
    sess.And("pull_request.head_branch=?", opts.HeadBranch)
}

So knope sends head=myowner:release-1.2.3 while the stored head_branch is release-1.2.3. They never compare equal → empty list → existing_pulls.first() is None → create_pull_request → the forge finds the existing unmerged PR and returns 409 Conflict (ctx.Error(http.StatusConflict, "GetUnmergedPullRequest", err)).

Worth noting: Gitea/Forgejo does accept the owner:branch form, but only on a different endpoint — GET /repos/{owner}/{repo}/pulls/{base}/{head}, which splits on : explicitly. knope does not call that one.

The GitHub backend is unaffected: owner:branch is correct for GitHub's API.

Impact

Any prepare-release-style workflow that maintains a long-lived release PR on Gitea/Forgejo fails on every run after the first. Because the branch is usually force-pushed before CreatePullRequest, the PR content is already current and the 409 is cosmetically harmless — but the step exits non-zero, so CI must special-case the error to stay green, and the documented title/body refresh silently never happens.

Suggested fix

Send the bare branch name on the Gitea backend:

("head", current_branch),

The base filter and the same-repo assumption already make the owner prefix redundant here. (If cross-repo head support is ever wanted, GET /pulls/{base}/{head} is the endpoint that accepts owner:branch.)

Versions

• knope 0.23.0 (knope-x86_64-unknown-linux-musl)
• Forgejo 16.0.1 (Gitea-compatible API)
• Same-repo release branch, [gitea] backend, PAT in GITEA_TOKEN

I verified the relevant code is identical on main at the time of filing.

Secondary note (not part of this report)

While reading the backend I noticed all Gitea calls authenticate via the ?access_token= query parameter (create_release.rs, list_issues.rs, create_pull_request.rs). PR #1902 ("use Authorization header for Gitea API calls to support Forgejo/Codeberg") was closed unmerged on 2026-05-24, so this remains the current behaviour. Query-parameter token auth is a long-standing deprecation candidate in Gitea/Forgejo; if it were removed the backend would stop working entirely. Flagging it as an observation only — happy to open a separate issue if that would be more useful.