fix(actions)!: require merged PR to bypass fork PR approval gate (#38010) (#38041)

Backport #38010 by @bircni

`ifNeedApproval` in `services/actions/notifier_helper.go` decided
whether a
fork PR's workflow run had to wait for maintainer approval. The bypass
clause
counted any prior `approved_by > 0` run for `(repo_id,
trigger_user_id)`, so
the very first Approve-and-run click on a contributor's fork PR
permanently
trusted that user for every future fork PR in the same repository —
including
PRs whose only change is the workflow YAML itself.

Approving a workflow *run* is not the same as merging *code*. This
change
aligns the gate with GitHub Actions' first-time-contributor model: trust
is
granted only after the user has had a pull request merged in the repo.

## Behavior change

- **Before**: one approval = permanent trust for that user in that repo.
- **After**: every fork PR is gated until the contributor has at least
one
  merged PR in the repo.

Existing already-approved runs and merged PRs continue to work; only the
trust criterion for *future* fork PRs changes. Maintainers who rely on
the
implicit "approve once" trust will see the approval banner reappear
until
they merge a PR from that contributor.

---------

Signed-off-by: bircni <bircni@icloud.com>
Co-authored-by: bircni <bircni@icloud.com>

services/actions/notifier_helper.go

@@ -399,6 +399,24 @@ func notifyPackage(ctx context.Context, sender *user_model.User, pd *packages_mo
 }
 
 func ifNeedApproval(ctx context.Context, run *actions_model.ActionRun, repo *repo_model.Repository, user *user_model.User) (bool, error) {
+	canWrite := func(ctx context.Context, repo *repo_model.Repository, user *user_model.User) (bool, error) {
+		perm, err := access_model.GetDoerRepoPermission(ctx, repo, user)
+		if err != nil {
+			return false, err
+		}
+		return perm.CanWrite(unit_model.TypeActions), nil
+	}
+	return ifNeedApprovalWith(ctx, run, repo, user, canWrite, issues_model.HasMergedPullRequestInRepo)
+}
+
+func ifNeedApprovalWith(
+	ctx context.Context,
+	run *actions_model.ActionRun,
+	repo *repo_model.Repository,
+	user *user_model.User,
+	canWriteActions func(context.Context, *repo_model.Repository, *user_model.User) (bool, error),
+	hasMergedPR func(context.Context, int64, int64) (bool, error),
+) (bool, error) {
 	// 1. don't need approval if it's not a fork PR
 	// 2. don't need approval if the event is `pull_request_target` since the workflow will run in the context of base branch
 	// 		see https://docs.github.com/en/actions/managing-workflow-runs/approving-workflow-runs-from-public-forks#about-workflow-runs-from-public-forks
@@ -413,27 +431,24 @@ func ifNeedApproval(ctx context.Context, run *actions_model.ActionRun, repo *rep
 	}
 
 	// don't need approval if the user can write
-	if perm, err := access_model.GetDoerRepoPermission(ctx, repo, user); err != nil {
+	if ok, err := canWriteActions(ctx, repo, user); err != nil {
 		return false, fmt.Errorf("GetDoerRepoPermission: %w", err)
-	} else if perm.CanWrite(unit_model.TypeActions) {
+	} else if ok {
 		log.Trace("do not need approval because user %d can write", user.ID)
 		return false, nil
 	}
 
-	// don't need approval if the user has been approved before
-	if count, err := db.Count[actions_model.ActionRun](ctx, actions_model.FindRunOptions{
-		RepoID:        repo.ID,
-		TriggerUserID: user.ID,
-		Approved:      true,
-	}); err != nil {
-		return false, fmt.Errorf("CountRuns: %w", err)
-	} else if count > 0 {
-		log.Trace("do not need approval because user %d has been approved before", user.ID)
+	// trust the user only after a merged PR — matching GitHub Actions. Approving one
+	// fork PR's run must not implicitly trust later fork PRs that replace the workflow.
+	if merged, err := hasMergedPR(ctx, repo.ID, user.ID); err != nil {
+		return false, fmt.Errorf("HasMergedPullRequestInRepo: %w", err)
+	} else if merged {
+		log.Trace("do not need approval because user %d has a merged pull request in repo %d", user.ID, repo.ID)
 		return false, nil
 	}
 
 	// otherwise, need approval
-	log.Trace("need approval because it's the first time user %d triggered actions", user.ID)
+	log.Trace("need approval because user %d has no merged pull request in repo %d", user.ID, repo.ID)
 	return true, nil
 }
 

services/actions/notifier_helper_test.go

@@ -0,0 +1,102 @@
+// Copyright 2026 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package actions
+
+import (
+	"context"
+	"errors"
+	"testing"
+
+	actions_model "code.gitea.io/gitea/models/actions"
+	repo_model "code.gitea.io/gitea/models/repo"
+	user_model "code.gitea.io/gitea/models/user"
+	actions_module "code.gitea.io/gitea/modules/actions"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestIfNeedApproval(t *testing.T) {
+	alwaysWrite := func(_ context.Context, _ *repo_model.Repository, _ *user_model.User) (bool, error) {
+		return true, nil
+	}
+	neverWrite := func(_ context.Context, _ *repo_model.Repository, _ *user_model.User) (bool, error) {
+		return false, nil
+	}
+	hasMerged := func(_ context.Context, _, _ int64) (bool, error) { return true, nil }
+	noMerged := func(_ context.Context, _, _ int64) (bool, error) { return false, nil }
+	errPerm := errors.New("perm error")
+	errMerge := errors.New("merge error")
+
+	forkRun := &actions_model.ActionRun{IsForkPullRequest: true, TriggerEvent: actions_module.GithubEventPullRequest}
+	nonForkRun := &actions_model.ActionRun{IsForkPullRequest: false, TriggerEvent: actions_module.GithubEventPullRequest}
+	prTargetRun := &actions_model.ActionRun{IsForkPullRequest: true, TriggerEvent: actions_module.GithubEventPullRequestTarget}
+
+	repo := &repo_model.Repository{ID: 1}
+	normalUser := &user_model.User{ID: 10}
+	restrictedUser := &user_model.User{ID: 11, IsRestricted: true}
+
+	t.Run("not a fork PR never needs approval", func(t *testing.T) {
+		need, err := ifNeedApprovalWith(t.Context(), nonForkRun, repo, normalUser, alwaysWrite, hasMerged)
+		require.NoError(t, err)
+		assert.False(t, need)
+	})
+
+	t.Run("pull_request_target never needs approval even when fork", func(t *testing.T) {
+		need, err := ifNeedApprovalWith(t.Context(), prTargetRun, repo, normalUser, alwaysWrite, hasMerged)
+		require.NoError(t, err)
+		assert.False(t, need)
+	})
+
+	t.Run("restricted user always needs approval", func(t *testing.T) {
+		need, err := ifNeedApprovalWith(t.Context(), forkRun, repo, restrictedUser, alwaysWrite, hasMerged)
+		require.NoError(t, err)
+		assert.True(t, need)
+	})
+
+	t.Run("fork PR with write permission does not need approval", func(t *testing.T) {
+		need, err := ifNeedApprovalWith(t.Context(), forkRun, repo, normalUser, alwaysWrite, noMerged)
+		require.NoError(t, err)
+		assert.False(t, need)
+	})
+
+	t.Run("fork PR with merged PR but no write permission does not need approval", func(t *testing.T) {
+		need, err := ifNeedApprovalWith(t.Context(), forkRun, repo, normalUser, neverWrite, hasMerged)
+		require.NoError(t, err)
+		assert.False(t, need)
+	})
+
+	t.Run("fork PR with no write and no merged PR needs approval", func(t *testing.T) {
+		need, err := ifNeedApprovalWith(t.Context(), forkRun, repo, normalUser, neverWrite, noMerged)
+		require.NoError(t, err)
+		assert.True(t, need)
+	})
+
+	t.Run("canWriteActions error is propagated", func(t *testing.T) {
+		failWrite := func(_ context.Context, _ *repo_model.Repository, _ *user_model.User) (bool, error) {
+			return false, errPerm
+		}
+		_, err := ifNeedApprovalWith(t.Context(), forkRun, repo, normalUser, failWrite, noMerged)
+		require.ErrorIs(t, err, errPerm)
+	})
+
+	t.Run("hasMergedPR error is propagated", func(t *testing.T) {
+		failMerge := func(_ context.Context, _, _ int64) (bool, error) { return false, errMerge }
+		_, err := ifNeedApprovalWith(t.Context(), forkRun, repo, normalUser, neverWrite, failMerge)
+		require.ErrorIs(t, err, errMerge)
+	})
+
+	t.Run("restricted user skips permission check entirely", func(t *testing.T) {
+		// The perm and merge functions must not be called for a restricted user.
+		called := false
+		trackWrite := func(_ context.Context, _ *repo_model.Repository, _ *user_model.User) (bool, error) {
+			called = true
+			return true, nil
+		}
+		need, err := ifNeedApprovalWith(t.Context(), forkRun, repo, restrictedUser, trackWrite, noMerged)
+		require.NoError(t, err)
+		assert.True(t, need)
+		assert.False(t, called, "permission check must not run for restricted user")
+	})
+}