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]>

act/runner/expression.go

@@ -248,6 +248,14 @@ func inputsFromEnv(env map[string]string) map[string]any {
 func getEvaluatorInputs(rc *RunContext, stepInputs map[string]any, ghc *model.GithubContext) map[string]any {
 	inputs := map[string]any{}
 
+	// only a called workflow's job itself takes the inputs Gitea resolved,
+	// composite actions copy its Config but have their own `inputs`
+	if rc.Config.WorkflowCallInputs != nil && rc.Parent == nil {
+		maps.Copy(inputs, rc.Config.WorkflowCallInputs)
+		maps.Copy(inputs, stepInputs)
+		return inputs
+	}
+
 	maps.Copy(inputs, rc.workflowCallInputs)
 	maps.Copy(inputs, stepInputs)