tokio_xmpp: properly process <stream:error/> while waiting for features

Before this, a stream error would not be readable by user code, as the
`recv_features()` function would not even attempt to parse it. This
change allows application code to react to stream errors which are
received before stream features are received.

skip-changelog, because there's no release with the xmlstream module
yet.

tokio-xmpp/src/error.rs

@@ -6,9 +6,11 @@ use hickory_resolver::{
 use sasl::client::MechanismError as SaslMechanismError;
 use std::io;
 
+use xmpp_parsers::stream_error::ReceivedStreamError;
+
 use crate::{
     connect::ServerConnectorError, jid, minidom,
-    parsers::sasl::DefinedCondition as SaslDefinedCondition,
+    parsers::sasl::DefinedCondition as SaslDefinedCondition, xmlstream::RecvFeaturesError,
 };
 
 /// Top-level error type
@@ -44,6 +46,8 @@ pub enum Error {
     Idna,
     /// Invalid IP/Port address
     Addr(AddrParseError),
+    /// Received a stream error
+    StreamError(ReceivedStreamError),
 }
 
 impl fmt::Display for Error {
@@ -65,6 +69,7 @@ impl fmt::Display for Error {
             #[cfg(feature = "dns")]
             Error::Idna => write!(fmt, "IDNA error"),
             Error::Addr(e) => write!(fmt, "Wrong network address: {e}"),
+            Error::StreamError(e) => write!(fmt, "{e}"),
         }
     }
 }
@@ -140,6 +145,15 @@ impl From<AddrParseError> for Error {
     }
 }
 
+impl From<RecvFeaturesError> for Error {
+    fn from(e: RecvFeaturesError) -> Self {
+        match e {
+            RecvFeaturesError::Io(e) => e.into(),
+            RecvFeaturesError::StreamError(e) => Self::StreamError(e),
+        }
+    }
+}
+
 /// XMPP protocol-level error
 #[derive(Debug)]
 pub enum ProtocolError {