R2 storage (generateFileURL per-collection) + filename normalization

dist/modules/storage/buildR2Storage.js

@@ -31,32 +31,31 @@ import { s3Storage } from '@payloadcms/storage-s3';
             return config;
         };
     }
-    // s3Storage wants Record<string, true> (the literal true, per collection),
-    // not Record<string, boolean>. Object.fromEntries widens true → boolean, so
-    // build the map with an explicitly-typed accumulator to keep the literal.
-    const collectionsConfig = {};
-    for (const slug of collections){
-        collectionsConfig[slug] = true;
-    }
-    // Public URL for served media. R2 is private by default; with a custom domain
+    // Public URL for served media. R2 is private by default; its S3 endpoint only
+    // accepts uploads and won't serve files (403). With a custom domain
     // (media.klient.pl → bucket) set R2_PUBLIC_URL so Payload generates URLs
-    // pointing there instead of the private S3 endpoint (which 403s on the front).
-    // Without it, uploads work but images don't display publicly. See docs/storage.md.
+    // pointing there. Without it, uploads work but images don't display publicly.
+    // See docs/storage.md.
     const publicUrl = process.env.R2_PUBLIC_URL?.replace(/\/$/, '') // strip trailing slash
     ;
+    // generateFileURL is a PER-COLLECTION option in @payloadcms/storage-s3 (not a
+    // top-level one) — R2 needs it to point served URLs at the custom domain
+    // instead of the private S3 endpoint. Each collection gets either `true`
+    // (plain offload) or an object carrying generateFileURL when a public URL is set.
+    const generateFileURL = publicUrl ? ({ filename, prefix })=>[
+            publicUrl,
+            prefix,
+            filename
+        ].filter(Boolean).join('/') : undefined;
+    const collectionsConfig = {};
+    for (const slug of collections){
+        collectionsConfig[slug] = generateFileURL ? {
+            generateFileURL
+        } : true;
+    }
     return s3Storage({
         bucket,
         collections: collectionsConfig,
-        ...publicUrl ? {
-            // generateFileURL overrides the stored/returned URL to the CDN domain.
-            // Params come from Payload's storage plugin; type them explicitly since
-            // the callback shape isn't inferred here (would be implicit any).
-            generateFileURL: ({ filename, prefix })=>[
-                    publicUrl,
-                    prefix,
-                    filename
-                ].filter(Boolean).join('/')
-        } : {},
         config: {
             credentials: {
                 accessKeyId,