httpd: Infer mime type of file blob in file_by_oid handler

Instead of relying on the mime_type query string the endpoint should try
to infer the file type.

radicle-httpd/Cargo.lock

@@ -375,6 +375,17 @@ dependencies = [
  "shlex",
 ]
 
+[[package]]
+name = "cfb"
+version = "0.7.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d38f2da7a0a2c4ccf0065be06397cc26a81f4e528be095826eee9d4adbb8c60f"
+dependencies = [
+ "byteorder",
+ "fnv",
+ "uuid",
+]
+
 [[package]]
 name = "cfg-if"
 version = "1.0.0"
@@ -1005,6 +1016,15 @@ dependencies = [
  "hashbrown",
 ]
 
+[[package]]
+name = "infer"
+version = "0.16.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bc150e5ce2330295b8616ce0e3f53250e53af31759a9dbedad1621ba29151847"
+dependencies = [
+ "cfb",
+]
+
 [[package]]
 name = "inout"
 version = "0.1.3"
@@ -1683,6 +1703,7 @@ dependencies = [
  "chrono",
  "flate2",
  "hyper",
+ "infer",
  "lexopt",
  "lru",
  "nonempty",
@@ -2564,6 +2585,12 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "uuid"
+version = "1.12.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b3758f5e68192bb96cc8f9b7e2c2cfdabb435499a28499a42f8f984092adad4b"
+
 [[package]]
 name = "valuable"
 version = "0.1.0"

radicle-httpd/Cargo.toml

@@ -27,6 +27,7 @@ base64 = { version = "0.22.1" }
 chrono = { version = "0.4.38", default-features = false, features = ["clock"] }
 flate2 = { version = "1" }
 hyper = { version = "1.4", default-features = false }
+infer = { version = "0.16.0" }
 lexopt = { version = "0.3.0" }
 lru = { version = "0.12.4" }
 nonempty = { version = "0.9.0", features = ["serialize"] }

radicle-httpd/src/raw.rs

@@ -161,7 +161,7 @@ fn blob_response(
 async fn file_by_oid_handler(
     Path((rid, oid)): Path<(RepoId, Oid)>,
     State(profile): State<Arc<Profile>>,
-    Query(qs): Query<RawQuery>,
+    Query(_qs): Query<RawQuery>,
 ) -> impl IntoResponse {
     let storage = &profile.storage;
     let repo = storage.repository(rid)?;
@@ -172,6 +172,8 @@ async fn file_by_oid_handler(
     }
 
     let blob = repo.blob(oid)?;
+    let content = blob.content();
+    let mime = infer::get(content).map(|i| i.mime_type().to_string());
     let mut response_headers = HeaderMap::new();
 
     if blob.size() > MAX_BLOB_SIZE {
@@ -180,10 +182,10 @@ async fn file_by_oid_handler(
 
     response_headers.insert(
         header::CONTENT_TYPE,
-        HeaderValue::from_str(&qs.mime.unwrap_or("application/octet-stream".to_string()))?,
+        HeaderValue::from_str(&mime.unwrap_or("application/octet-stream".to_string()))?,
     );
 
-    Ok::<_, Error>((StatusCode::OK, response_headers, blob.content().to_vec()))
+    Ok::<_, Error>((StatusCode::OK, response_headers, content.to_vec()))
 }
 
 #[cfg(test)]