URI schemes are case-insensitive (RFC 3986, section 3.1), but several
places matched only lowercase "data:" or "file:":
- Text.Pandoc.URI.pBase64DataURI (also used by isURI)
- downloadOrRead: the fast-path prefix check and the parseURI
fallback for data: and file: URIs
- Text.Pandoc.App.Input.readSource: file:, http:, and https: URIs
given as input sources
- Text.Pandoc.MediaBag: canonicalize's fast path and insertMedia's
data-URI branch
Previously, e.g. DATA:image/gif;base64,... would be handed to openURL
and the image dropped, and a large uppercase data URI would also force
a full parseURI in MediaBag.canonicalize. Now such URIs are handled
the same as their lowercase equivalents. Added a test case.
Co-Authored-By: Claude <noreply@anthropic.com>
