Make Module#prepend affect ancestor chain even if argument already included in receiver

Previously, if a class included a module and then prepended the
same module, the prepend had no effect.  This changes the behavior
so that the prepend has an effect unless the module is already
prepended the receiver.

While here, rename the origin_seen variable in include_modules_at,
since it is misleading. The variable tracks whether c has been seen,
not whether the origin of klass has been.

Fixes [Bug #17423]

0 files changed, 0 insertions, 0 deletions