GFDL-1x licenses make it fail

[nanotower]

i.e. satisfies('GFDL-1.1-invariants-or-later', 'MIT OR GPL-1.0') crashes. I've checked both arguments against spdx-expression-validate and both are valid.
Both of them came out of spdx-license-ids, which is obtaining the valid SPDX list right from the source.

[kemitchell]

The issue is in normalizeGPLIdentifiers.

The way SPDX has identified the GFDLs, GFDL-1.1-invariants alone isn't a valid identifier. It has to have -or-later or -only. So merely stripping -or-later or -only off the end doesn't leave a valid license ID.