Run cargo clippy on whole project (#322)

* Run cargo clippy on plume-common

Run clippy on plume-common and adjuste code accordingly

* Run cargo clippy on plume-model

Run clippy on plume-model and adjuste code accordingly

* Reduce need for allocation in plume-common

* Reduce need for allocation in plume-model

add a quick compilation failure if no database backend is enabled

* Run cargo clippy on plume-cli

* Run cargo clippy on plume

src/routes/session.rs

@@ -49,15 +49,15 @@ struct LoginForm {
 #[post("/login", data = "<data>")]
 fn create(conn: DbConn, data: LenientForm<LoginForm>, flash: Option<FlashMessage>, mut cookies: Cookies) -> Result<Redirect, Template> {
     let form = data.get();
-    let user = User::find_by_email(&*conn, form.email_or_name.to_string())
-        .or_else(|| User::find_local(&*conn, form.email_or_name.to_string()));
+    let user = User::find_by_email(&*conn, &form.email_or_name)
+        .or_else(|| User::find_local(&*conn, &form.email_or_name));
     let mut errors = match form.validate() {
         Ok(_) => ValidationErrors::new(),
         Err(e) => e
     };
     
     if let Some(user) = user.clone() {
-        if !user.auth(form.password.clone()) {
+        if !user.auth(&form.password) {
             let mut err = ValidationError::new("invalid_login");
             err.message = Some(Cow::from("Invalid username or password"));
             errors.add("email_or_name", err)
@@ -65,7 +65,7 @@ fn create(conn: DbConn, data: LenientForm<LoginForm>, flash: Option<FlashMessage
     } else {
         // Fake password verification, only to avoid different login times
         // that could be used to see if an email adress is registered or not
-        User::get(&*conn, 1).map(|u| u.auth(form.password.clone()));
+        User::get(&*conn, 1).map(|u| u.auth(&form.password));
 
         let mut err = ValidationError::new("invalid_login");
         err.message = Some(Cow::from("Invalid username or password"));
@@ -83,7 +83,7 @@ fn create(conn: DbConn, data: LenientForm<LoginForm>, flash: Option<FlashMessage
             } else {
                 None
             })
-            .unwrap_or("/".to_owned());
+            .unwrap_or_else(|| "/".to_owned());
 
         let uri = Uri::parse(&destination)
             .map(|x| x.into_owned())
@@ -108,6 +108,8 @@ fn create(conn: DbConn, data: LenientForm<LoginForm>, flash: Option<FlashMessage
 
 #[get("/logout")]
 fn delete(mut cookies: Cookies) -> Redirect {
-    cookies.get_private(AUTH_COOKIE).map(|cookie| cookies.remove_private(cookie));
+    if let Some(cookie) = cookies.get_private(AUTH_COOKIE) {
+        cookies.remove_private(cookie);
+    }
     Redirect::to("/")
 }