Session should write percent encoded cookies and add cookie middleware test (#393)

* Should write percent encoded cookies to HTTP response

* Add cookie middleware test

src/httpresponse.rs

@@ -161,7 +161,7 @@ impl HttpResponse {
         let mut count: usize = 0;
         for v in vals {
             if let Ok(s) = v.to_str() {
-                if let Ok(c) = Cookie::parse(s) {
+                if let Ok(c) = Cookie::parse_encoded(s) {
                     if c.name() == name {
                         count += 1;
                         continue;
@@ -327,7 +327,7 @@ impl<'a> Iterator for CookieIter<'a> {
     #[inline]
     fn next(&mut self) -> Option<Cookie<'a>> {
         for v in self.iter.by_ref() {
-            if let Ok(c) = Cookie::parse(v.to_str().ok()?) {
+            if let Ok(c) = Cookie::parse_encoded(v.to_str().ok()?) {
                 return Some(c);
             }
         }

src/middleware/session.rs

@@ -410,7 +410,7 @@ impl CookieSessionInner {
         }
 
         for cookie in jar.delta() {
-            let val = HeaderValue::from_str(&cookie.to_string())?;
+            let val = HeaderValue::from_str(&cookie.encoded().to_string())?;
             resp.headers_mut().append(header::SET_COOKIE, val);
         }
 
@@ -464,6 +464,9 @@ impl CookieSessionInner {
 /// all session data is lost. The constructors will panic if the key is less
 /// than 32 bytes in length.
 ///
+/// The backend relies on `cookie` crate to create and read cookies.
+/// By default all cookies are percent encoded, but certain symbols may
+/// cause troubles when reading cookie, if they are not properly percent encoded.
 ///
 /// # Example
 ///