olc-recover-compound fails on non-compound codes

This is inconvenient:

(olc-recover-compound "3RQW9VH8+9C")
=> wrong-type-argument

It also means that olc-shorten-combound can generate output that olc-recover-compound can't handle.

added enhancement label

mentioned in merge request !1 (merged)

created merge request !1 (merged) to address this issue

closed via commit 4eedef44

mentioned in issue #2 (closed)

reopened

The fix is not a fix. It fixes other things, but not this thing.

mentioned in commit a84a9b7e

mentioned in merge request !3 (merged)

closed via commit 9a4d1985