Fix (webkit) encode URLs with dot in path name to circumvent Safari

overriding headers (fixes opening e.g. PDF files)

Author: zefhemel

client/spaces/http_space_primitives.ts

@@ -12,6 +12,31 @@ import { headersToFileMeta } from "../lib/util.ts";
 
 const defaultFetchTimeout = 30000; // 30 seconds
 
+// WebKit (Safari, WKWebView) strips custom response headers (X-Last-Modified,
+// etc.) when it recognizes a file extension in the URL. Encoding the last dot
+// as %2E prevents this; the server decodes it transparently.
+const isWebKit = typeof navigator !== "undefined" &&
+  /AppleWebKit/.test(navigator.userAgent) &&
+  !/Chrome/.test(navigator.userAgent);
+
+function encodeExtensionDot(url: string): string {
+  // Only encode the file extension dot, not dots in the path prefix (like /.fs).
+  // Manipulate the raw string — Safari's URL.pathname setter rejects %2E.
+  const fsIdx = url.indexOf("/.fs/");
+  if (fsIdx < 0) return url;
+  const afterFs = fsIdx + 5; // position after "/.fs/"
+  const filePart = url.substring(afterFs);
+  const qIdx = filePart.indexOf("?");
+  const path = qIdx >= 0 ? filePart.substring(0, qIdx) : filePart;
+  const rest = qIdx >= 0 ? filePart.substring(qIdx) : "";
+  const lastDot = path.lastIndexOf(".");
+  if (lastDot > path.lastIndexOf("/")) {
+    return url.substring(0, afterFs) +
+      path.substring(0, lastDot) + "%2E" + path.substring(lastDot + 1) + rest;
+  }
+  return url;
+}
+
 export class HttpSpacePrimitives implements SpacePrimitives {
   constructor(
     readonly url: string,
@@ -40,6 +65,9 @@ export class HttpSpacePrimitives implements SpacePrimitives {
     }
 
     try {
+      if (isWebKit) {
+        url = encodeExtensionDot(url);
+      }
       options.signal = AbortSignal.timeout(fetchTimeout);
       options.redirect = "manual";
       const result = await fetch(url, options);