hook to limit size of changeset(s)?

[Hans Fangohr]

Dear all,

I have discovered Mercurial only recently, and am delighted!  Thank
you to everybody who help with this, and thank you also for
documenting hg well.

It appeared to be a good idea to have a check that no very large files
are commited (such as binaries) etc. So I thought I could write a hook
(using pretxncommit or pretxnchangegroup) that that will look at the
size of the patch of the latest attempted commit (i.e. something like
"hg log -p $HG_NODE | wc --bytes" and combines this with an if
statement to see whether it exceeds a given upper size limit. This
works (for changes in non-binary files) and for the examples I have
tested.

Here are my questions:

  - is this overall a good idea? (My motivation is to exclude bogus
  commits with large files from people who are either unexperienced or careless [which
  may well include myself].) Will this always work? Are there issues
  with merging branches (such that a collection of changesets appears
  to be a large change?)

  - the chosen approach (using 'log -p' will not give enough output
  data for binary files as it just states that a binary file has
  changed). I could use 'hg diff --text -r $HG_NODE -r XXX' but don't
  know which other revision XXX I should compare against.

I have been digging around a bit and couldn't find this covered
anywhere. Maybe it is just a bad idea?

Any comments welcome.

Thanks,


Hans