Regression - PDFs download initiated on click (should be open in new tab)

zogstrip · June 10, 2026, 2:10pm

We were being inconsistent with the display type depending on whether you were using S3 or not. That should be fixed by

github.com/discourse/discourse

FIX: Serve inline-safe uploads inline on the local file store (#40739)

main ← fix-inline-safe-uploads-local-store

opened 02:09PM - 10 Jun 26 UTC

ZogStriP

+47 -32

Inline-safe uploads (images, PDFs, audio and video) served from the local file s…tore were sent with `Content-Disposition: attachment`, so clicking a PDF link downloaded the file instead of opening it in the browser. This was inconsistent with the S3 store, which already serves these files inline via `FileStore::S3Store.content_disposition_for`, and it left simple self-hosted (single-container, no S3/CDN) sites unable to open PDFs inline. The cause was in `UploadsController#send_file_local_upload`: it only set the disposition to `attachment` for unsafe types, and to `inline` when `?inline=1` was passed, leaving it unset otherwise. Rails' `send_file` defaults an unset disposition to `attachment`, so inline-safe files fell through to a download. This serves inline-safe files with `Content-Disposition: inline` by default, mirroring the S3 store. The `attachment` disposition and the `sandbox;` Content-Security-Policy header are now scoped to the files that are actually forced to download: unsafe types (HTML, SVG, XML, ...) and explicit downloads (`?dl=1`). The redundant `params[:inline]` branch is removed, since inline-safe files are now served inline by default.

(cc @david)

The fact that clicking on a file opens automatically in another tab is more a product question.

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Regression - PDFs download initiated on click (should be open in new tab)

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