ExitCode returned inconsistently

Throughout the code base, it is inconsistent if execution of some shell action 
returns an ExitCode, or if it sets the last exit code shell state. In many 
cases, especially in Execute.hs, it needs to do both: We need the shell state 
set to meet the needs of the shell language ($? must be set), and we need it to 
compute control flow (for things like && and ||).

However, i suspect that in most other places, we really explicitly want one or 
the other of these treatments for ExitCode: Either it should be set as part of 
the shell state... or returned as part of some computation, but not set in 
state. Really, this needs to be scrutinized, and perhaps even encoded in the 
type system.

Original issue reported on code.google.com by mark.len...@gmail.com on 17 Nov 2012 at 7:12

kustomzone / plush

ExitCode returned inconsistently #9