Fix some unsoundness

This improves the sound implementation of `fn route`.
Previously this function would iterate twice but we
can reduce the overhead without using `unsafe`.

src/application.rs

@@ -335,33 +335,34 @@ where
         T: FromRequest<S> + 'static,
     {
         {
-            let parts = self.parts.as_mut().expect("Use after finish");
+            let parts: &mut ApplicationParts<S> = self.parts.as_mut().expect("Use after finish");
 
-            // get resource handler
+            let out = {
-            let mut found = false;
+                // get resource handler
-            for &mut (ref pattern, ref handler) in &mut parts.resources {
+                let mut iterator = parts.resources.iter_mut();
-                if handler.is_some() && pattern.pattern() == path {
-                    found = true;
-                    break;
-                }
-            }
 
-            if !found {
+                loop {
-                let mut handler = ResourceHandler::default();
+                    if let Some(&mut (ref pattern, ref mut handler)) = iterator.next() {
-                handler.method(method).with(f);
+                        if let Some(ref mut handler) = *handler {
-                let pattern = Resource::new(handler.get_name(), path);
+                            if pattern.pattern() == path {
-                parts.resources.push((pattern, Some(handler)));
+                                handler.method(method).with(f);
-            } else {
+                                break None;
-                for &mut (ref pattern, ref mut handler) in &mut parts.resources {
+                            }
-                    if let Some(ref mut handler) = *handler {
-                        if pattern.pattern() == path {
-                            handler.method(method).with(f);
-                            break;
                         }
+                    } else {
+                        let mut handler = ResourceHandler::default();
+                        handler.method(method).with(f);
+                        let pattern = Resource::new(handler.get_name(), path);
+                        break Some((pattern, Some(handler)));
                     }
                 }
+            };
+
+            if let Some(out) = out {
+                parts.resources.push(out);
             }
         }
+
         self
     }
 

src/multipart.rs

@@ -1,5 +1,5 @@
 //! Multipart requests support
-use std::cell::RefCell;
+use std::cell::{RefCell, UnsafeCell};
 use std::marker::PhantomData;
 use std::rc::Rc;
 use std::{cmp, fmt};
@@ -590,7 +590,7 @@ where
 }
 
 struct PayloadRef<S> {
-    payload: Rc<PayloadHelper<S>>,
+    payload: Rc<UnsafeCell<PayloadHelper<S>>>,
 }
 
 impl<S> PayloadRef<S>
@@ -599,7 +599,7 @@ where
 {
     fn new(payload: PayloadHelper<S>) -> PayloadRef<S> {
         PayloadRef {
-            payload: Rc::new(payload),
+            payload: Rc::new(payload.into()),
         }
     }
 
@@ -609,7 +609,7 @@ where
     {
         if s.current() {
             let payload: &mut PayloadHelper<S> =
-                unsafe { &mut *(self.payload.as_ref() as *const _ as *mut _) };
+                unsafe { &mut *self.payload.get() };
             Some(payload)
         } else {
             None

src/server/h1writer.rs

@@ -73,12 +73,11 @@ impl<T: AsyncWrite, H: 'static> H1Writer<T, H> {
         self.flags.contains(Flags::KEEPALIVE) && !self.flags.contains(Flags::UPGRADE)
     }
 
-    fn write_data(&mut self, data: &[u8]) -> io::Result<usize> {
+    fn write_data(stream: &mut T, data: &[u8]) -> io::Result<usize> {
         let mut written = 0;
         while written < data.len() {
-            match self.stream.write(&data[written..]) {
+            match stream.write(&data[written..]) {
                 Ok(0) => {
-                    self.disconnected();
                     return Err(io::Error::new(io::ErrorKind::WriteZero, ""));
                 }
                 Ok(n) => {
@@ -243,7 +242,16 @@ impl<T: AsyncWrite, H: 'static> Writer for H1Writer<T, H> {
                 if self.flags.contains(Flags::UPGRADE) {
                     if self.buffer.is_empty() {
                         let pl: &[u8] = payload.as_ref();
-                        let n = self.write_data(pl)?;
+                        let n = match Self::write_data(&mut self.stream, pl) {
+                            Err(err) => {
+                                if err.kind() == io::ErrorKind::WriteZero {
+                                    self.disconnected();
+                                }
+
+                                return Err(err);
+                            }
+                            Ok(val) => val,
+                        };
                         if n < pl.len() {
                             self.buffer.extend_from_slice(&pl[n..]);
                             return Ok(WriterState::Done);
@@ -284,9 +292,18 @@ impl<T: AsyncWrite, H: 'static> Writer for H1Writer<T, H> {
     #[inline]
     fn poll_completed(&mut self, shutdown: bool) -> Poll<(), io::Error> {
         if !self.buffer.is_empty() {
-            let buf: &[u8] =
+            let written = {
-                unsafe { &mut *(self.buffer.as_ref() as *const _ as *mut _) };
+                match Self::write_data(&mut self.stream, self.buffer.as_ref()) {
-            let written = self.write_data(buf)?;
+                    Err(err) => {
+                        if err.kind() == io::ErrorKind::WriteZero {
+                            self.disconnected();
+                        }
+    
+                        return Err(err);
+                    }
+                    Ok(val) => val,
+                }
+            };
             let _ = self.buffer.split_to(written);
             if shutdown && !self.buffer.is_empty()
                 || (self.buffer.len() > self.buffer_capacity)