Revert a specific transaction changes

Question

I have the following stream structure:

Parent-+->Child1
       |
       +->Child2

There are changes that were promoted from stream Child1 to stream Parent and broke build of the stream Child2.

I need to revert these changes only in Child2.

Exactly I need to do the following (Gig-style):

1. Get a diff over the transaction that broke the build (in inverted way)
2. Apply it to stream Child2

Locking of the Child2 to the transaction is not a variant, because there are some changes that were done after the broken transaction was made.

Answer 1

Hang a workspace off of Parent. Right click on the Parent stream -> Show History -> Select transaction you wish to revert -> Click on Revert. Choose the workspace you hung off the Parent stream. Once the subtractive merge completes, hang this workspace off of Child2 -> Update workspace -> Promote changes. You have now removed the bad transaction from the Child2 stream.