From f85b451fcf5dbcab6bd4c53b7ca93344a69f5e80 Mon Sep 17 00:00:00 2001
From: Emmanuel Gil Peyrot <linkmauve@linkmauve.fr>
Date: Tue, 31 Oct 2017 15:47:38 +0000
Subject: [PATCH] Add a new check_no_attributes macro, to avoid the empty list.

---
 src/chatstates.rs   | 2 +-
 src/data_forms.rs   | 8 ++++----
 src/lib.rs          | 8 +++++++-
 src/pubsub/event.rs | 2 +-
 4 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/src/chatstates.rs b/src/chatstates.rs
index 995cd11e..e226f21d 100644
--- a/src/chatstates.rs
+++ b/src/chatstates.rs
@@ -40,7 +40,7 @@ impl TryFrom<Element> for ChatState {
     fn try_from(elem: Element) -> Result<ChatState, Error> {
         check_ns_only!(elem, "chatstate", ns::CHATSTATES);
         check_no_children!(elem, "chatstate");
-        check_no_unknown_attributes!(elem, "chatstate", []);
+        check_no_attributes!(elem, "chatstate");
         Ok(match elem.name() {
             "active" => ChatState::Active,
             "composing" => ChatState::Composing,
diff --git a/src/data_forms.rs b/src/data_forms.rs
index e3a68f46..a54be9c2 100644
--- a/src/data_forms.rs
+++ b/src/data_forms.rs
@@ -105,14 +105,14 @@ impl TryFrom<Element> for Field {
         for element in elem.children() {
             if element.is("value", ns::DATA_FORMS) {
                 check_no_children!(element, "value");
-                check_no_unknown_attributes!(element, "value", []);
+                check_no_attributes!(element, "value");
                 field.values.push(element.text());
             } else if element.is("required", ns::DATA_FORMS) {
                 if field.required {
                     return Err(Error::ParseError("More than one required element."));
                 }
                 check_no_children!(element, "required");
-                check_no_unknown_attributes!(element, "required", []);
+                check_no_attributes!(element, "required");
                 field.required = true;
             } else if element.is("option", ns::DATA_FORMS) {
                 if !field.is_list() {
@@ -184,14 +184,14 @@ impl TryFrom<Element> for DataForm {
                     return Err(Error::ParseError("More than one title in form element."));
                 }
                 check_no_children!(child, "title");
-                check_no_unknown_attributes!(child, "title", []);
+                check_no_attributes!(child, "title");
                 form.title = Some(child.text());
             } else if child.is("instructions", ns::DATA_FORMS) {
                 if form.instructions.is_some() {
                     return Err(Error::ParseError("More than one instructions in form element."));
                 }
                 check_no_children!(child, "instructions");
-                check_no_unknown_attributes!(child, "instructions", []);
+                check_no_attributes!(child, "instructions");
                 form.instructions = Some(child.text());
             } else if child.is("field", ns::DATA_FORMS) {
                 let field = Field::try_from(child.clone())?;
diff --git a/src/lib.rs b/src/lib.rs
index 5b52da05..fee722cc 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -154,6 +154,12 @@ macro_rules! check_no_children {
     );
 }
 
+macro_rules! check_no_attributes {
+    ($elem:ident, $name:tt) => (
+        check_no_unknown_attributes!($elem, $name, []);
+    );
+}
+
 macro_rules! check_no_unknown_attributes {
     ($elem:ident, $name:tt, [$($attr:tt),*]) => (
         for (_attr, _) in $elem.attrs() {
@@ -182,7 +188,7 @@ macro_rules! generate_empty_element {
             fn try_from(elem: Element) -> Result<$elem, Error> {
                 check_self!(elem, $name, $ns);
                 check_no_children!(elem, $name);
-                check_no_unknown_attributes!(elem, $name, []);
+                check_no_attributes!(elem, $name);
                 Ok($elem)
             }
         }
diff --git a/src/pubsub/event.rs b/src/pubsub/event.rs
index 9f8b1e4c..74b59ae6 100644
--- a/src/pubsub/event.rs
+++ b/src/pubsub/event.rs
@@ -143,7 +143,7 @@ impl TryFrom<Element> for PubSubEvent {
 
     fn try_from(elem: Element) -> Result<PubSubEvent, Error> {
         check_self!(elem, "event", ns::PUBSUB_EVENT);
-        check_no_unknown_attributes!(elem, "event", []);
+        check_no_attributes!(elem, "event");
 
         let mut payload = None;
         for child in elem.children() {