[subbu@earth lib] echo '[[it:foo|foo]]' | node parse --wt2wt
[[it:foo|it:foo]]
[subbu@earth lib] echo '[[:wikt:foo|foo]]' | node parse --wt2wt
[[wikt:foo|foo]]
Version: unspecified
Severity: normal
[subbu@earth lib] echo '[[it:foo|foo]]' | node parse --wt2wt
[[it:foo|it:foo]]
[subbu@earth lib] echo '[[:wikt:foo|foo]]' | node parse --wt2wt
[[wikt:foo|foo]]
Version: unspecified
Severity: normal
The : prefix is not needed in the second case, and we are relying on selser to preserve unnecessary escaping. I'm inclined to close this as worksforme.
Change 124888 had a related patch set uploaded by Subramanya Sastry:
Bug fix to serialization of interwiki links