enhance(actions): improve reusable workflow uses handling and cancellation (#37991)

Follow up #37478

## Changes

1. #37478 doesn't support absolute URL in `uses`. This PR provides
partial support for URL-style reusable workflow references. A reusable
workflow can now be referenced by an absolute URL, as long as it points
to the local Gitea instance:

```yaml
jobs:
  call:
    uses: https://your-gitea.example.com/OWNER/REPO/.gitea/workflows/ci.yaml@v1
```

2. Show an error message in the UI for invalid `uses`.

<img width="1600" alt="image"
src="https://github.com/user-attachments/assets/21b34e61-bf10-4af1-b9fd-4ee4e9fde049"
/>

3. Fix reusable caller cancellation issue. A reusable caller's status is
aggregated from its children, so cancellation should processes a
caller's descendants deepest-first.

---------

Signed-off-by: Zettat123 <zettat123@gmail.com>
Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>
Co-authored-by: bircni <bircni@icloud.com>
Co-authored-by: Giteabot <teabot@gitea.io>

models/actions/run_job.go

@@ -4,6 +4,7 @@
 package actions
 
 import (
+	"cmp"
 	"context"
 	"fmt"
 	"slices"
@@ -671,18 +672,18 @@ func cancelOneJob(ctx context.Context, job *ActionRunJob) (*ActionRunJob, error)
 func cancelReusableCaller(ctx context.Context, caller *ActionRunJob) ([]*ActionRunJob, error) {
 	cancelledJobs := make([]*ActionRunJob, 0)
 
-	if c, err := cancelOneJob(ctx, caller); err != nil {
-		return cancelledJobs, err
-	} else if c != nil {
-		cancelledJobs = append(cancelledJobs, c)
-	}
-
 	attemptJobs, err := GetRunJobsByRunAndAttemptID(ctx, caller.RunID, caller.RunAttemptID)
 	if err != nil {
 		return cancelledJobs, err
 	}
 
-	for _, c := range CollectAllDescendantJobs(caller, attemptJobs) {
+	// Cancel descendants deepest-first, then the caller: a caller's status is aggregated from its children,
+	// so each child must reach its final state before its parent caller is re-aggregated.
+	// A child's ID always exceeds its parent's, so descending ID is a valid deepest-first order.
+	descendants := CollectAllDescendantJobs(caller, attemptJobs)
+	slices.SortFunc(descendants, func(a, b *ActionRunJob) int { return cmp.Compare(b.ID, a.ID) })
+
+	for _, c := range descendants {
 		cancelled, err := cancelOneJob(ctx, c)
 		if err != nil {
 			return cancelledJobs, err
@@ -691,5 +692,11 @@ func cancelReusableCaller(ctx context.Context, caller *ActionRunJob) ([]*ActionR
 			cancelledJobs = append(cancelledJobs, cancelled)
 		}
 	}
+
+	if c, err := cancelOneJob(ctx, caller); err != nil {
+		return cancelledJobs, err
+	} else if c != nil {
+		cancelledJobs = append(cancelledJobs, c)
+	}
 	return cancelledJobs, nil
 }

models/actions/run_job_test.go

@@ -131,3 +131,69 @@ func TestGetPriorAttemptChildrenByParent(t *testing.T) {
 		assertAttempt1Children(t, out)
 	})
 }
+
+// A reusable caller subtree with a Blocked descendant (e.g. a nested caller stuck on an invalid `uses:`) must aggregate to Cancelled, when the run is cancelled.
+func TestCancelJobs_NestedBlockedReusableCaller(t *testing.T) {
+	require.NoError(t, unittest.PrepareTestDatabase())
+	ctx := t.Context()
+
+	run := &ActionRun{
+		Title:         "cancel-nested-caller",
+		RepoID:        4,
+		Index:         9701,
+		OwnerID:       1,
+		WorkflowID:    "caller.yaml",
+		TriggerUserID: 1,
+		Ref:           "refs/heads/master",
+		CommitSHA:     "c2d72f548424103f01ee1dc02889c1e2bff816b0",
+		Event:         "push",
+		TriggerEvent:  "push",
+		EventPayload:  "{}",
+		Status:        StatusBlocked,
+	}
+	require.NoError(t, db.Insert(ctx, run))
+
+	attempt := &ActionRunAttempt{RepoID: run.RepoID, RunID: run.ID, Attempt: 1, TriggerUserID: 1, Status: StatusBlocked}
+	require.NoError(t, db.Insert(ctx, attempt))
+	run.LatestAttemptID = attempt.ID
+	require.NoError(t, UpdateRun(ctx, run, "latest_attempt_id"))
+
+	newJob := func(name string, attemptJobID, parentID int64, callUses string) *ActionRunJob {
+		job := &ActionRunJob{
+			RunID:            run.ID,
+			RunAttemptID:     attempt.ID,
+			RepoID:           run.RepoID,
+			OwnerID:          run.OwnerID,
+			CommitSHA:        run.CommitSHA,
+			Name:             name,
+			JobID:            name,
+			Attempt:          1,
+			Status:           StatusBlocked,
+			AttemptJobID:     attemptJobID,
+			IsReusableCaller: true,
+			CallUses:         callUses,
+			ParentJobID:      parentID,
+		}
+		require.NoError(t, db.Insert(ctx, job))
+		return job
+	}
+
+	// outer: a valid top-level caller that expanded; inner: a nested caller stuck Blocked (invalid uses, never expands).
+	outer := newJob("outer", 1, 0, "./.gitea/workflows/lib.yml")
+	inner := newJob("inner", 2, outer.ID, "https://other.example.com/o/r/.gitea/workflows/ci.yml@v1")
+
+	// Cancel all jobs of the attempt, ordered by id (parent before child).
+	jobs, err := GetRunJobsByRunAndAttemptID(ctx, run.ID, attempt.ID)
+	require.NoError(t, err)
+	_, err = CancelJobs(ctx, jobs)
+	require.NoError(t, err)
+
+	for _, j := range []*ActionRunJob{outer, inner} {
+		got := unittest.AssertExistsAndLoadBean(t, &ActionRunJob{ID: j.ID})
+		assert.Equal(t, StatusCancelled, got.Status, "job %q should be cancelled", j.JobID)
+	}
+	gotAttempt := unittest.AssertExistsAndLoadBean(t, &ActionRunAttempt{ID: attempt.ID})
+	assert.Equal(t, StatusCancelled, gotAttempt.Status, "attempt must aggregate to Cancelled")
+	gotRun := unittest.AssertExistsAndLoadBean(t, &ActionRun{ID: run.ID})
+	assert.Equal(t, StatusCancelled, gotRun.Status, "run must aggregate to Cancelled, not stay Blocked")
+}