Preserve whitespaces for string primitive types

Author: ggodlewski

Changelog.md

@@ -20,6 +20,9 @@ Now references to entities (as predefined, such as `<`, as user-defined) repo
 Caller can parse the content of the entity and stream events from it as it is required by the
 XML specification. See the updated `custom_entities` example!
 
+Implement whitespace behavior in the standard, which says string primitive types should
+preserve whitespace, while all other primitives have collapse behavior.
+
 ### New Features
 
 - [#863]: Add `Attributes::into_map_access(&str)` and `Attributes::into_deserializer()` when `serialize`

src/de/map.rs

@@ -262,6 +262,7 @@ where
                 QNameDeserializer::from_attr(QName(&slice[key]), decoder, &mut self.de.key_buf)?;
             seed.deserialize(de).map(Some)
         } else {
+            self.de.skip_whitespaces()?;
             // try getting from events (<key>value</key>)
             match self.de.peek()? {
                 // We shouldn't have both `$value` and `$text` fields in the same
@@ -318,6 +319,7 @@ where
                     debug_assert_eq!(self.start.name(), e.name());
                     // Consume End
                     self.de.next()?;
+                    self.de.skip_whitespaces()?;
                     Ok(None)
                 }
                 // We cannot get `Eof` legally, because we always inside of the
@@ -563,7 +565,7 @@ where
         // We cannot use result of `peek()` directly because of borrow checker
         let _ = self.map.de.peek()?;
         match self.map.de.last_peeked() {
-            DeEvent::Text(t) if t.is_empty() => visitor.visit_none(),
+            DeEvent::Text(t) if t.is_blank() => visitor.visit_none(),
             DeEvent::Start(start) if self.map.should_skip_subtree(start) => {
                 self.map.de.skip_next_tree()?;
                 visitor.visit_none()
@@ -935,6 +937,7 @@ where
         T: DeserializeSeed<'de>,
     {
         loop {
+            self.map.de.skip_whitespaces()?;
             break match self.map.de.peek()? {
                 // If we see a tag that we not interested, skip it
                 #[cfg(feature = "overlapped-lists")]