fix check_file() / check_buffer() which were broken if the header con…

…tained a comment

this was broken by commit ec2119e: allow comments to be attached to elements

autosar-data/src/lib.rs

@@ -488,11 +488,14 @@ mod test {
 
         // file containing a valid arxml header -> true
         let header = r#"<?xml version="1.0" encoding="utf-8"?>
+        <!-- comment --><!-- comment 2 -->
         <AUTOSAR xsi:schemaLocation="http://autosar.org/schema/r4.0 AUTOSAR_00050.xsd" xmlns="http://autosar.org/schema/r4.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">"#;
         let arxml_file = dir.path().with_file_name("file.arxml");
         File::create(&arxml_file)
             .and_then(|mut file| file.write(header.as_bytes()))
             .unwrap();
         assert!(check_file(arxml_file));
+
+        assert!(check_buffer(header.as_bytes()));
     }
 }

autosar-data/src/parser.rs

@@ -830,7 +830,12 @@ impl<'a> ArxmlParser<'a> {
         let mut lexer = ArxmlLexer::new(self.buffer, self.filename.clone());
 
         if let Ok(ArxmlEvent::ArxmlHeader(_)) = self.next(&mut lexer) {
-            if let Ok(ArxmlEvent::BeginElement(elemname, attributes_text)) = self.next(&mut lexer) {
+            // skip any comments
+            let mut arxmlevent = self.next(&mut lexer);
+            while let Ok(ArxmlEvent::Comment(..)) = arxmlevent {
+                arxmlevent = self.next(&mut lexer);
+            }
+            if let Ok(ArxmlEvent::BeginElement(elemname, attributes_text)) = arxmlevent {
                 if let Ok(ElementName::Autosar) = ElementName::from_bytes(elemname) {
                     if let Ok(attributes) = self.parse_attribute_text(ElementType::ROOT, attributes_text) {
                         if self.parse_file_header(&attributes).is_ok() {