commit: abort when a committemplate is not changed If a committemplate is provided and no message is provided on the command line, and no edits are made to the commit template, then abort the commit.

localrepo.commit: disallow commit when driver-resolved files exist This code will not currently be activated because there's no code to mark files as driver-resolved in core. This point is also somewhat hard to plug into from extensions.

merge.mergestate: add a generator for driver-resolved files Just like for unresolved files above, we need to be able to tell what files are driver-resolved.

hook: for python hooks, also return whether an exception was raised The hook code treats python hooks raising an exception and returning True as the exact same. This is OK for hooks themselves, but other code that wants to invoke external code using the same underlying code is a bit more interested in making a distinction.

hook.runhooks: return a dict of result values This will be useful to other calling code that would be interested in what the individual hooks return.

hook: factor out determination of hooks from running them This will allow other code to run a predetermined series of hooks.

mq: generate patch names from first line of description Avoid the pointless numeric rev.diff patch names. Instead, do like mbox extension does and create meaningful patch names.