Doesn't work if Drupal is served from a subdirectory

MR!93 added.

Possible dup https://www.drupal.org/project/stage_file_proxy/issues/3499660 🐛 Files are not proxied when Drupal is not in the webroot Needs work

Either way probably should have a test

Hmm, definitely a dupe, I tried searching for something similar but my keyword-fu was probably not on its peak. I will comment there, I think this patch is cleaner and rely on a core function rather than string replacements.

Rebased

Issue was already fixed in the latest version of the module.

I kind of feel that this is a better fix, it's doing a lot of things that are really not necessary:

diff --git a/src/DownloadManager.php b/src/DownloadManager.php
index ae73c0c2cb17e267bf318f6a428810a10d2908b3..bf5a00e1a7762606b52ea5c6402f69d0874fa728 100644
--- a/src/DownloadManager.php
+++ b/src/DownloadManager.php
@@ -140,11 +140,7 @@ final class DownloadManager implements DownloadManagerInterface {
    * {@inheritdoc}
    */
   public function filePublicPath(): string {
-    $request = $this->requestStack->getCurrentRequest();
-    $filesDir = PublicStream::baseUrl();
-    $host = $request->getSchemeAndHttpHost();
-    $basePath = $request->getBasePath();
-    return str_replace($host . $basePath . '/', '', $filesDir);
+    return PublicStream::basePath();
   }
 
   /**

Why do all that to remove things from baseUrl() when base basePath() already gives yo what you want?