Previous commit (8ace5f4) passed `return: ["id", "url"]` to APIv3
Attachment.get. APIv3 expects `return` as a comma-separated string
("id,url"); arrays are v4 syntax. Civi caught the type mismatch but
its error-rendering pathway then crashed on htmlentities() (which
was passed the offending array), producing a 500 with an HTML error
page rather than a clean JSON error.
Fix: pass return as "id,url" and add sequential:1 (canonical v3 client
shape — values come back as an array). The civi3 helper already
normalizes either response shape, but sequential matches what real
APIv3 clients send.
Logs to confirm after deploy:
- Success: no "[staff/report] Attachment.get (v3) failed" warning.
- File links resolve directly without bouncing off the
/civicrm/webform-mw/file extension route.
Joel Brock
6c3e8dd6a0