core: check content-encoding for proxy

packages/hydrooj/package.json

@@ -1,6 +1,6 @@
 {
     "name": "hydrooj",
-    "version": "3.2.30",
+    "version": "3.2.31",
     "bin": "bin/hydrooj.js",
     "main": "src/loader",
     "module": "src/loader",

packages/hydrooj/src/handler/misc.ts

@@ -107,6 +107,7 @@ export class FSDownloadHandler extends Handler {
             this.response.etag = file.etag;
             this.response.body = await storage.get(target);
             this.response.type = file['Content-Type'] || type;
+            if (file['Content-Encoding']) this.response.addHeader('Content-Encoding', file['Content-Encoding']);
             if (!noDisposition) this.response.disposition = `attachment; filename=${encodeURIComponent(filename)}`;
         } else {
             this.response.redirect = await storage.signDownloadLink(

packages/hydrooj/src/handler/problem.ts

@@ -629,6 +629,7 @@ export class ProblemFileDownloadHandler extends ProblemDetailHandler {
             this.response.etag = file.etag;
             this.response.body = await storage.get(target);
             this.response.type = file['Content-Type'] || fileType;
+            if (file['Content-Encoding']) this.response.addHeader('Content-Encoding', file['Content-Encoding']);
             if (!noDisposition) this.response.disposition = `attachment; filename=${encodeURIComponent(filename)}`;
         } else {
             this.response.redirect = await storage.signDownloadLink(