fix: restore the caller's event and inputs in reusable workflow jobs (#1250)

Fixes https://github.com/go-gitea/gitea/issues/38705

Gitea side: https://github.com/go-gitea/gitea/pull/39452

Jobs of a called workflow currently see `gitea.event_name == "workflow_call"`, and their `gitea.event.inputs` is replaced by the caller's `with:`. On GitHub they keep the caller's event, and their `inputs` are the run's `workflow_dispatch` inputs overlaid with the caller's `with:`.

For compatibility with older runners, Gitea keeps sending that form and adds a `gitea_workflow_call` key with the original trigger event name and inputs of the run, and the `inputs` Gitea resolved for the job. When the key is present, the runner restores `gitea.event_name` and `gitea.event.inputs` from it, and uses the resolved `inputs` for the job's expressions and the setup log.

Without that key (older Gitea, or jobs outside called workflows), nothing changes.

Reviewed-on: https://gitea.com/gitea/runner/pulls/1250
Reviewed-by: bircni <[email protected]>
Reviewed-by: silverwind <[email protected]>
Co-authored-by: Zettat123 <[email protected]>

internal/app/run/setup.go

@@ -56,10 +56,15 @@ func (r *Runner) setupLines(task *runnerv1.Task) []string {
 	return append(lines, "::endgroup::")
 }
 
-// inputLines lists the inputs the run was triggered with, as workflow_dispatch and workflow_call
-// carry them in the event payload. Empty when the event has none.
+// inputLines lists the inputs of the job: those Gitea resolved for a called workflow's job,
+// or the ones a workflow_dispatch event carries in its payload. Empty when there are none.
 func inputLines(fields map[string]*structpb.Value) []string {
 	inputs := fields["event"].GetStructValue().GetFields()["inputs"].GetStructValue().GetFields()
+	// For a called workflow's job, restore its inputs from `gitea_workflow_call`.
+	// See https://github.com/go-gitea/gitea/pull/39452.
+	if workflowCall := fields["gitea_workflow_call"].GetStructValue(); workflowCall != nil {
+		inputs = workflowCall.GetFields()["inputs"].GetStructValue().GetFields()
+	}
 	if len(inputs) == 0 {
 		return nil
 	}