fix(actions): correctness and hardening fixes (#38518) (#38631)

Backport #38518 by @bircni

Various fixes to actions

1. **Cap total jobs per run in reusable-workflow expansion** — only
nesting depth was capped, so fan-out + nested reusable workflows could
explode job-row inserts and exhaust the DB from a single push. Now
enforces `MaxJobNumPerRun` in the insert path.
2. **Reject rerun-failed when a run has no failed jobs** — an empty job
list meant "re-run everything", so `rerun-failed` on a green run re-ran
all jobs. Now errors (web + API).
3. **Don't adopt external commit statuses into the legacy hash** — the
pre-#35699 Context-only hash matched API-posted statuses too, collapsing
two same-named workflows into one check. Now limited to Actions-user
rows.
4. **Don't cut post-cancel cleanup short in `StopEndlessTasks`** — the
sweep force-stopped just-cancelled jobs mid-cleanup. Now targets
`StatusRunning` only; stalled cancels stay covered by `StopZombieTasks`.
5. **Avoid redundant run reload in `GenerateGiteaContext`** — resolving
`github.triggering_actor` reloaded the run already passed in. Now loads
only the trigger user via new `ActionRunAttempt.LoadTriggerUser`.

Co-authored-by: bircni <bircni@icloud.com>
Co-authored-by: Zettat123 <zettat123@gmail.com>
Co-authored-by: silverwind <me@silverwind.io>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

services/actions/context_test.go

@@ -9,7 +9,9 @@ import (
 
 	actions_model "gitea.dev/models/actions"
 	"gitea.dev/models/db"
+	repo_model "gitea.dev/models/repo"
 	"gitea.dev/models/unittest"
+	user_model "gitea.dev/models/user"
 	"gitea.dev/modules/json"
 	api "gitea.dev/modules/structs"
 
@@ -318,3 +320,39 @@ func TestFindTaskNeeds(t *testing.T) {
 	assert.Equal(t, "abc", ret["job1"].Outputs["output_a"])
 	assert.Equal(t, "bbb", ret["job1"].Outputs["output_b"])
 }
+
+// TestGenerateGiteaContext_NilAttempt verifies that, with no explicit attempt,
+// use GetLatestAttempt to load the latest attempt and resolve attempt-related context variables.
+func TestGenerateGiteaContext_NilAttempt(t *testing.T) {
+	require.NoError(t, unittest.PrepareTestDatabase())
+
+	repo := unittest.AssertExistsAndLoadBean(t, &repo_model.Repository{ID: 4})
+	require.NoError(t, repo.LoadOwner(t.Context()))
+	actor := unittest.AssertExistsAndLoadBean(t, &user_model.User{ID: 1})     // initiated the run
+	triggerer := unittest.AssertExistsAndLoadBean(t, &user_model.User{ID: 2}) // initiated the latest attempt
+
+	run := &actions_model.ActionRun{
+		RepoID: repo.ID, Repo: repo, OwnerID: repo.OwnerID,
+		TriggerUserID: actor.ID, TriggerUser: actor,
+		WorkflowID: "test.yml", Index: 99600, Ref: "refs/heads/main",
+		CommitSHA: "c2d72f548424103f01ee1dc02889c1e2bff816b0", TriggerEvent: "push",
+		Status: actions_model.StatusRunning,
+	}
+	require.NoError(t, db.Insert(t.Context(), run))
+	attempt := &actions_model.ActionRunAttempt{
+		RepoID: repo.ID, RunID: run.ID, Attempt: 3, TriggerUserID: triggerer.ID, Status: actions_model.StatusRunning,
+	}
+	require.NoError(t, db.Insert(t.Context(), attempt))
+	run.LatestAttemptID = attempt.ID
+	job := &actions_model.ActionRunJob{
+		RunID: run.ID, RunAttemptID: attempt.ID, AttemptJobID: 1, RepoID: repo.ID, OwnerID: repo.OwnerID,
+		Name: "j", JobID: "j", Attempt: attempt.Attempt, Status: actions_model.StatusRunning,
+	}
+	require.NoError(t, db.Insert(t.Context(), job))
+
+	// attempt == nil forces the fallback lookup via run.GetLatestAttempt.
+	gitCtx := GenerateGiteaContext(t.Context(), run, nil, job)
+	assert.Equal(t, actor.Name, gitCtx["actor"])
+	assert.Equal(t, triggerer.Name, gitCtx["triggering_actor"])
+	assert.Equal(t, "3", gitCtx["run_attempt"])
+}