Reduce string duplication in compression code
This cuts down on string copies and allows buffers (instead of strings)
to be passed into the compression code
abort: repository a/.hg not found!
255
requesting all changes
abort: error: Connection refused
255
abort: repository a/.hg not found!
255
abort: destination '../a' already exists
1
abort: repository a/.hg not found!
255
abort: destination 'q' already exists