The doc-diff script immediately resolves its two endpoints
to actual object ids, so that we can reuse cached results
even if they appear under a different name. But we still use
the original name the user fed us when running "git
checkout" in our temporary worktree. This can lead to
confusing results:
- the namespace inside the worktree is different than the
one outside. In particular, "./doc-diff origin HEAD"
will resolve HEAD inside the worktree, whose detached
HEAD will be pointing at origin! As a result, such a
diff would always be empty.
- worse, we will store this result under the oid we got by
resolving HEAD in the main worktree, thus polluting our
cache
- we didn't pass --detach, which meant that using a branch
name would cause us to actually check out that branch,
making it unavailable to other worktrees.
We can solve this by feeding the already-resolved object id
to git-checkout. That naturally forces a detached HEAD, but
just to make clear our expectation, let's explicitly pass
--detach.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We already advise people to make sure their documentation
formats correctly. Let's point them at the doc-diff script,
which can help with that.
Let's also put a brief note in the script about its purpose,
since that otherwise can only be found in the original
commit message. Along with the existing -h/usage text,
that's hopefully enough for developers to make use of it.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
After making a change to the documentation, it's easy to
forget to check the rendered version to make sure it was
formatted as you intended. And simply doing a diff between
the two built versions is less trivial than you might hope:
- diffing the roff or html output isn't particularly
readable; what we really care about is what the end user
will see
- you have to tweak a few build variables to avoid
spurious differences (e.g., version numbers, build
times)
Let's provide a script that builds and installs the manpages
for two commits, renders the results using "man", and diffs
the result. Since this is time-consuming, we'll also do our
best to avoid repeated work, keeping intermediate results
between runs.
Some of this could probably be made a little less ugly if we
built support into Documentation/Makefile. But by relying
only on "make install-man" working, this script should work
for generating a diff between any two versions, whether they
include this script or not.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
