fix: panic due to an invalid memory address when injectSecretRecursive encounters nil values (#5699)

pipeline/frontend/yaml/compiler/settings/params.go

@@ -194,7 +194,9 @@ func injectSecret(v map[string]any, getSecretValue func(name string) (string, er
 // it iterates recursively over them too, using injectSecret internally.
 func injectSecretRecursive(v any, getSecretValue func(name string) (string, error)) (any, error) {
 	t := reflect.TypeOf(v)
-
+	if t == nil {
+		return v, nil
+	}
 	if !isComplex(t.Kind()) {
 		return v, nil
 	}

pipeline/frontend/yaml/compiler/settings/params_test.go

@@ -304,3 +304,21 @@ func TestSecretMappingComplexMapWithSecrets(t *testing.T) {
 	assert.Equal(t, expectedJSON, secretMapping["PLUGIN_CONFIG"])
 	assert.NotContains(t, secretMapping, "PLUGIN_SIMPLE_VAR")
 }
+
+func TestComplexTypesWithNilValuesWontPanic(t *testing.T) {
+	from := map[string]any{
+		"config": []any{
+			"copy a b",
+			map[string]any{
+				"foo": nil,
+			},
+		},
+	}
+
+	got := map[string]string{}
+	expectedJSON := `["copy a b",{"foo":null}]`
+
+	err := ParamsToEnv(from, got, "PLUGIN_", true, nil, nil)
+	assert.NoError(t, err)
+	assert.Equal(t, expectedJSON, got["PLUGIN_CONFIG"])
+}