do no-op post_commit test in wrapper

This speeds up web commits by 1/4th of a second or so, since perl does
not have to start up for the post commit hook.

perl's locking is completly FuBar, since it's impossible to tell what perl
flock() really does, and thus difficult to write code in other languages
that interoperates with perl's locking. (Let alone interoperating with
existing fcntl locking from perl...)

In this particular case, I think I was able to find a way to avoid the
insanity, mostly. The C code does a true flock(2), and if perl is using an
incompatable lock method that does not use the same locking primative at
the kernel level, then the C code's test will fail, and it will go ahead
and run the perl code. Then the perl code's test will test the right thing.

On Debian, at least lately, perl's flock() does a true flock(2), so the
optimisation does work.

1 files changed, 2 insertions, 2 deletions

diff --git a/debian/changelog b/debian/changelog
index d8e26e4c9..63556c941 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -31,8 +31,8 @@ ikiwiki (2.68) UNRELEASED; urgency=low
   * external: RPC functions can be injected to replace exported functions.
   * Updated Spanish translation from the ever vigilant Victor Moral.
   * Updated Danish translation from Jonas Smedegaard. Closes: #503117
-  * Optimise the no-op post-commit hook in the web edit case by skipping
-    loading plugins. (Particularly a win when using external plugins.)
+  * Optimise the no-op post-commit hook, to speed up web edits by a fraction
+    of a second.
   * Add support for checking pushes from untrusted git committers. This can be
     used to set up anonymous git pushes, and other similar things.