Merge pull request #660 from Mingun/fix-580

Fix `UnexpectedEof` when deserialize `xs:list`s and newtypes

Changelog.md

@@ -20,6 +20,10 @@ MSRV bumped to 1.56! Crate now uses Rust 2021 edition.
 
 ### Bug Fixes
 
+- [#660]: Fixed incorrect deserialization of `xs:list`s from empty tags (`<tag/>`
+ or `<tag></tag>`). Previously an `DeError::UnexpectedEof")` was returned in that case
+- [#580]: Fixed incorrect deserialization of vectors of newtypes from sequences of tags.
+
 ### Misc Changes
 
 - [#643]: Bumped MSRV to 1.56. In practice the previous MSRV was incorrect in many cases.
@@ -32,11 +36,13 @@ MSRV bumped to 1.56! Crate now uses Rust 2021 edition.
  (and newly added `ElementWriter::write_inner_content_async` of course).
 
 [#545]: https://github.com/tafia/quick-xml/pull/545
+[#580]: https://github.com/tafia/quick-xml/issues/580
 [#619]: https://github.com/tafia/quick-xml/issues/619
 [#635]: https://github.com/tafia/quick-xml/pull/635
 [#643]: https://github.com/tafia/quick-xml/pull/643
 [#649]: https://github.com/tafia/quick-xml/pull/646
 [#651]: https://github.com/tafia/quick-xml/pull/651
+[#660]: https://github.com/tafia/quick-xml/pull/660
 
 
 ## 0.30.0 -- 2023-07-23

src/de/map.rs

@@ -373,6 +373,52 @@ macro_rules! forward {
 /// A deserializer for a value of map or struct. That deserializer slightly
 /// differently processes events for a primitive types and sequences than
 /// a [`Deserializer`].
+///
+/// This deserializer can see two kind of events at the start:
+/// - [`DeEvent::Text`]
+/// - [`DeEvent::Start`]
+///
+/// which represents two possible variants of items:
+/// ```xml
+/// <item>A tag item</item>
+/// A text item
+/// <yet another="tag item"/>
+/// ```
+///
+/// This deserializer are very similar to a [`SeqItemDeserializer`]. The only difference
+/// in the `deserialize_seq` method. This deserializer will act as an iterator
+/// over tags / text within it's parent tag, whereas the [`SeqItemDeserializer`]
+/// will represent sequences as an `xs:list`.
+///
+/// This deserializer processes items as following:
+/// - primitives (numbers, booleans, strings, characters) are deserialized either
+/// from a text content, or unwrapped from a one level of a tag. So, `123` and
+/// `<int>123</int>` both can be deserialized into an `u32`;
+/// - `Option`:
+/// - empty text of [`DeEvent::Text`] is deserialized as `None`;
+/// - everything else are deserialized as `Some` using the same deserializer,
+/// including `<tag/>` or `<tag></tag>`;
+/// - units (`()`) and unit structs consumes the whole text or element subtree;
+/// - newtype structs are deserialized by forwarding deserialization of inner type
+/// with the same deserializer;
+/// - sequences, tuples and tuple structs are deserialized by iterating within the
+/// parent tag and deserializing each tag or text content using [`SeqItemDeserializer`];
+/// - structs and maps are deserialized using new instance of [`MapAccess`];
+/// - enums:
+/// - in case of [`DeEvent::Text`] event the text content is deserialized as
+/// a `$text` variant. Enum content is deserialized from the text using
+/// [`SimpleTypeDeserializer`];
+/// - in case of [`DeEvent::Start`] event the tag name is deserialized as
+/// an enum tag, and the content inside are deserialized as an enum content.
+/// Depending on a variant kind deserialization is performed as:
+/// - unit variants: consuming text content or a subtree;
+/// - newtype variants: forward deserialization to the inner type using
+/// this deserializer;
+/// - tuple variants: call [`deserialize_tuple`] of this deserializer;
+/// - struct variants: call [`deserialize_struct`] of this deserializer.
+///
+/// [`deserialize_tuple`]: #method.deserialize_tuple
+/// [`deserialize_struct`]: #method.deserialize_struct
 struct MapValueDeserializer<'de, 'a, 'm, R, E>
 where
  R: XmlRead<'de>,
@@ -485,7 +531,6 @@ where
 
  forward!(deserialize_unit);
 
- forward!(deserialize_map);
  forward!(deserialize_struct(
  name: &'static str,
  fields: &'static [&'static str]
@@ -497,7 +542,6 @@ where
  ));
 
  forward!(deserialize_any);
- forward!(deserialize_ignored_any);
 
  fn deserialize_option<V>(self, visitor: V) -> Result<V::Value, DeError>
  where
@@ -506,6 +550,19 @@ where
  deserialize_option!(self.map.de, self, visitor)
  }
 
+ /// Forwards deserialization of the inner type. Always calls [`Visitor::visit_newtype_struct`]
+ /// with the same deserializer.
+ fn deserialize_newtype_struct<V>(
+ self,
+ _name: &'static str,
+ visitor: V,
+ ) -> Result<V::Value, Self::Error>
+ where
+ V: Visitor<'de>,
+ {
+ visitor.visit_newtype_struct(self)
+ }
+
  /// Deserializes each `<tag>` in
  /// ```xml
  /// <any-tag>
@@ -716,7 +773,59 @@ where
 
 ////////////////////////////////////////////////////////////////////////////////////////////////////
 
-/// A deserializer for a single item of a sequence.
+/// A deserializer for a single item of a mixed sequence of tags and text.
+///
+/// This deserializer can see two kind of events at the start:
+/// - [`DeEvent::Text`]
+/// - [`DeEvent::Start`]
+///
+/// which represents two possible variants of items:
+/// ```xml
+/// <item>A tag item</item>
+/// A text item
+/// <yet another="tag item"/>
+/// ```
+///
+/// This deserializer are very similar to a [`MapValueDeserializer`]. The only difference
+/// in the `deserialize_seq` method. This deserializer will perform deserialization
+/// from the textual content (the text itself in case of [`DeEvent::Text`] event
+/// and the text between tags in case of [`DeEvent::Start`] event), whereas
+/// the [`MapValueDeserializer`] will iterate over tags / text within it's parent tag.
+///
+/// This deserializer processes items as following:
+/// - primitives (numbers, booleans, strings, characters) are deserialized either
+/// from a text content, or unwrapped from a one level of a tag. So, `123` and
+/// `<int>123</int>` both can be deserialized into an `u32`;
+/// - `Option`:
+/// - empty text of [`DeEvent::Text`] is deserialized as `None`;
+/// - everything else are deserialized as `Some` using the same deserializer,
+/// including `<tag/>` or `<tag></tag>`;
+/// - units (`()`) and unit structs consumes the whole text or element subtree;
+/// - newtype structs are deserialized as tuple structs with one element;
+/// - sequences, tuples and tuple structs are deserialized using [`SimpleTypeDeserializer`]
+/// (this is the difference):
+/// - in case of [`DeEvent::Text`] event text content passed to the deserializer directly;
+/// - in case of [`DeEvent::Start`] event the start and end tags are stripped,
+/// and text between them is passed to [`SimpleTypeDeserializer`]. If the tag
+/// contains something else other than text, an error is returned, but if it
+/// contains a text and something else (for example, `<item>text<tag/></item>`),
+/// then the trail is just ignored;
+/// - structs and maps are deserialized using new [`MapAccess`];
+/// - enums:
+/// - in case of [`DeEvent::Text`] event the text content is deserialized as
+/// a `$text` variant. Enum content is deserialized from the text using
+/// [`SimpleTypeDeserializer`];
+/// - in case of [`DeEvent::Start`] event the tag name is deserialized as
+/// an enum tag, and the content inside are deserialized as an enum content.
+/// Depending on a variant kind deserialization is performed as:
+/// - unit variants: consuming text content or a subtree;
+/// - newtype variants: forward deserialization to the inner type using
+/// this deserializer;
+/// - tuple variants: deserialize it as an `xs:list`;
+/// - struct variants: call [`deserialize_struct`] of this deserializer.
+///
+/// [`deserialize_tuple`]: #method.deserialize_tuple
+/// [`deserialize_struct`]: #method.deserialize_struct
 struct SeqItemDeserializer<'de, 'a, 'm, R, E>
 where
  R: XmlRead<'de>,
@@ -754,7 +863,6 @@ where
 
  forward!(deserialize_unit);
 
- forward!(deserialize_map);
  forward!(deserialize_struct(
  name: &'static str,
  fields: &'static [&'static str]
@@ -766,7 +874,6 @@ where
  ));
 
  forward!(deserialize_any);
- forward!(deserialize_ignored_any);
 
  fn deserialize_option<V>(self, visitor: V) -> Result<V::Value, DeError>
  where
@@ -775,6 +882,20 @@ where
  deserialize_option!(self.map.de, self, visitor)
  }
 
+ /// Forwards deserialization of the inner type. Always calls [`Visitor::visit_newtype_struct`]
+ /// with the [`SimpleTypeDeserializer`].
+ fn deserialize_newtype_struct<V>(
+ mut self,
+ _name: &'static str,
+ visitor: V,
+ ) -> Result<V::Value, Self::Error>
+ where
+ V: Visitor<'de>,
+ {
+ let text = self.read_string()?;
+ visitor.visit_newtype_struct(SimpleTypeDeserializer::from_text(text))
+ }
+
  /// This method deserializes a sequence inside of element that itself is a
  /// sequence element:
  ///
@@ -787,34 +908,12 @@ where
  /// ...
  /// </>
  /// ```
- fn deserialize_seq<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+ fn deserialize_seq<V>(mut self, visitor: V) -> Result<V::Value, Self::Error>
  where
  V: Visitor<'de>,
  {
- match self.map.de.next()? {
- DeEvent::Text(e) => {
- SimpleTypeDeserializer::from_text_content(e).deserialize_seq(visitor)
- }
- // This is a sequence element. We cannot treat it as another flatten
- // sequence if type will require `deserialize_seq` We instead forward
- // it to `xs:simpleType` implementation
- DeEvent::Start(e) => {
- let value = match self.map.de.next()? {
- DeEvent::Text(e) => {
- SimpleTypeDeserializer::from_text_content(e).deserialize_seq(visitor)
- }
- e => Err(DeError::Unsupported(
- format!("unsupported event {:?}", e).into(),
- )),
- };
- // TODO: May be assert that here we expect only matching closing tag?
- self.map.de.read_to_end(e.name())?;
- value
- }
- // SAFETY: we use that deserializer only when Start(element) or Text
- // event was peeked already
- _ => unreachable!(),
- }
+ let text = self.read_string()?;
+ SimpleTypeDeserializer::from_text(text).deserialize_seq(visitor)
  }
 
  #[inline]

src/de/mod.rs

@@ -1904,18 +1904,6 @@ macro_rules! deserialize_primitives {
  self.deserialize_unit(visitor)
  }
 
- /// Representation of the newtypes the same as one-element [tuple](#method.deserialize_tuple).
- fn deserialize_newtype_struct<V>(
- self,
- _name: &'static str,
- visitor: V,
- ) -> Result<V::Value, DeError>
- where
- V: Visitor<'de>,
- {
- self.deserialize_tuple(1, visitor)
- }
-
  /// Representation of tuples the same as [sequences](#method.deserialize_seq).
  fn deserialize_tuple<V>(self, _len: usize, visitor: V) -> Result<V::Value, DeError>
  where
@@ -1937,13 +1925,32 @@ macro_rules! deserialize_primitives {
  self.deserialize_tuple(len, visitor)
  }
 
+ /// Forwards deserialization to the [`deserialize_struct`](#method.deserialize_struct)
+ /// with empty name and fields.
+ #[inline]
+ fn deserialize_map<V>(self, visitor: V) -> Result<V::Value, DeError>
+ where
+ V: Visitor<'de>,
+ {
+ self.deserialize_struct("", &[], visitor)
+ }
+
  /// Identifiers represented as [strings](#method.deserialize_str).
  fn deserialize_identifier<V>(self, visitor: V) -> Result<V::Value, DeError>
  where
  V: Visitor<'de>,
  {
  self.deserialize_str(visitor)
  }
+
+ /// Forwards deserialization to the [`deserialize_unit`](#method.deserialize_unit).
+ #[inline]
+ fn deserialize_ignored_any<V>(self, visitor: V) -> Result<V::Value, DeError>
+ where
+ V: Visitor<'de>,
+ {
+ self.deserialize_unit(visitor)
+ }
  };
 }
 
@@ -2820,30 +2827,36 @@ where
  }
  }
 
- fn deserialize_enum<V>(
+ /// Forwards deserialization of the inner type. Always calls [`Visitor::visit_newtype_struct`]
+ /// with the same deserializer.
+ fn deserialize_newtype_struct<V>(
  self,
  _name: &'static str,
- _variants: &'static [&'static str],
  visitor: V,
  ) -> Result<V::Value, DeError>
  where
  V: Visitor<'de>,
  {
- visitor.visit_enum(var::EnumAccess::new(self))
+ visitor.visit_newtype_struct(self)
  }
 
- fn deserialize_seq<V>(self, visitor: V) -> Result<V::Value, DeError>
+ fn deserialize_enum<V>(
+ self,
+ _name: &'static str,
+ _variants: &'static [&'static str],
+ visitor: V,
+ ) -> Result<V::Value, DeError>
  where
  V: Visitor<'de>,
  {
- visitor.visit_seq(self)
+ visitor.visit_enum(var::EnumAccess::new(self))
  }
 
- fn deserialize_map<V>(self, visitor: V) -> Result<V::Value, DeError>
+ fn deserialize_seq<V>(self, visitor: V) -> Result<V::Value, DeError>
  where
  V: Visitor<'de>,
  {
- self.deserialize_struct("", &[], visitor)
+ visitor.visit_seq(self)
  }
 
  fn deserialize_option<V>(self, visitor: V) -> Result<V::Value, DeError>
@@ -2853,39 +2866,13 @@ where
  deserialize_option!(self, self, visitor)
  }
 
- /// Always call `visitor.visit_unit()` because returned value ignored in any case.
- ///
- /// This method consumes any single [event][DeEvent] except the [`Start`]
- /// event, in which case all events up to and including corresponding [`End`]
- /// event will be consumed.
- ///
- /// This method returns error if current event is [`End`] or [`Eof`].
- ///
- /// [`Start`]: DeEvent::Start
- /// [`End`]: DeEvent::End
- /// [`Eof`]: DeEvent::Eof
- fn deserialize_ignored_any<V>(self, visitor: V) -> Result<V::Value, DeError>
- where
- V: Visitor<'de>,
- {
- match self.next()? {
- DeEvent::Start(e) => self.read_to_end(e.name())?,
- DeEvent::End(e) => return Err(DeError::UnexpectedEnd(e.name().as_ref().to_owned())),
- DeEvent::Eof => return Err(DeError::UnexpectedEof),
- _ => (),
- }
- visitor.visit_unit()
- }
-
  fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, DeError>
  where
  V: Visitor<'de>,
  {
  match self.peek()? {
- DeEvent::Start(_) => self.deserialize_map(visitor),
- // Redirect to deserialize_unit in order to consume an event and return an appropriate error
- DeEvent::End(_) | DeEvent::Eof => self.deserialize_unit(visitor),
- _ => self.deserialize_string(visitor),
+ DeEvent::Text(_) => self.deserialize_str(visitor),
+ _ => self.deserialize_map(visitor),
  }
  }
 }