Fix 'Limits' deserialization.

Fixes rwf2#2268.

core/lib/src/data/limits.rs

@@ -122,8 +122,9 @@ use crate::http::uncased::Uncased;
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
 #[serde(transparent)]
 pub struct Limits {
-    #[serde(with = "figment::util::vec_tuple_map")]
-    limits: Vec<(Uncased<'static>, ByteUnit)>
+    #[serde(deserialize_with = "Limits::deserialize")]
+    #[serde(serialize_with = "figment::util::vec_tuple_map::serialize")]
+    limits: Vec<(Uncased<'static>, ByteUnit)>,
 }
 
 impl Default for Limits {
@@ -299,6 +300,16 @@ impl Limits {
 
         None
     }
+
+    /// Deserialize a `Limits` vector from a map. Ensures that the resulting
+    /// vector is properly sorted for futures lookups via binary search.
+    fn deserialize<'de, D>(de: D) -> Result<Vec<(Uncased<'static>, ByteUnit)>, D::Error>
+        where D: serde::Deserializer<'de>
+    {
+        let mut limits = figment::util::vec_tuple_map::deserialize(de)?;
+        limits.sort();
+        Ok(limits)
+    }
 }
 
 impl fmt::Display for Limits {

core/lib/tests/deserialize-limits-issue-2268.rs

@@ -0,0 +1,31 @@
+use rocket::config::Config;
+use rocket::data::Limits;
+use rocket::figment::{providers::Serialized, Figment};
+use ubyte::ToByteUnit;
+
+#[test]
+fn deserialize_mixed_case_limits_should_work() {
+    let figment = Figment::default()
+        .merge(Serialized::default("key1", 1.kibibytes()))
+        .merge(Serialized::default("key5", 5.kibibytes()))
+        .merge(Serialized::default("key3", 3.kibibytes()))
+        .merge(Serialized::default("Key2", 2.kibibytes()))
+        .merge(Serialized::default("Key4", 4.kibibytes()))
+        .merge(Serialized::default("Key6", 6.kibibytes()));
+
+    let limits: Limits = figment.extract().unwrap();
+    assert_eq!(limits.get("key1"), Some(1.kibibytes()));
+    assert_eq!(limits.get("key2"), Some(2.kibibytes()));
+    assert_eq!(limits.get("key3"), Some(3.kibibytes()));
+    assert_eq!(limits.get("key4"), Some(4.kibibytes()));
+    assert_eq!(limits.get("key5"), Some(5.kibibytes()));
+    assert_eq!(limits.get("key6"), Some(6.kibibytes()));
+}
+
+#[test]
+fn deserialize_extra_limits_in_config_should_work() {
+    let extra_limits = Limits::new().limit("Phactory", 1.kibibytes());
+    let figment = Config::figment().merge(("limits", extra_limits));
+    let config = Config::from(figment);
+    assert_eq!(config.limits.get("Phactory"), Some(1.kibibytes()));
+}