view contrib/plan9/9diff @ 29494:3b5389ef5cfe

perf: define util.safehasattr forcibly for Mercurial earlier than 1.9.3

Before this patch, using util.safehasattr() prevents perf.py from
being loaded by Mercurial earlier than 1.9.3 (or 94b200a11cf7),
because util.safehasattr() isn't available in such Mercurial, even
though there are some code paths for Mercurial earlier than 1.9.3.

For example, setting "_prereadsize" attribute in perfindex() and
perfnodelookup() is effective only with Mercurial earlier than 1.8 (or
61c9bc3da402).

This patch is a preparation for using util.safehasattr() safely in
subsequent patches.

This patch defines util.safehasattr() forcibly without examining
whether it is available or not, because:

  - examining existence of "safehasattr" safely itself needs similar logic
  - safehasattr() is small enough to define locally

#!/bin/rc
# 9diff - Mercurial extdiff wrapper for diff(1)

rfork e

fn getfiles {
	cd $1 &&
	for(f in `{du -as | awk '{print $2}'})
		test -f $f && echo `{cleanname $f}
}

fn usage {
	echo >[1=2] usage: 9diff [diff options] parent child root
	exit usage
}

opts=()
while(~ $1 -*){
	opts=($opts $1)
	shift
}
if(! ~ $#* 3)
	usage

# extdiff will set the parent and child to a single file if there is
# only one change. If there are multiple changes, directories will be
# set. diff(1) does not cope particularly with directories; instead we
# do the recursion ourselves and diff each file individually.
if(test -f $1)
	diff $opts $1 $2
if not{
	# extdiff will create a snapshot of the working copy to prevent
	# conflicts during the diff. We circumvent this behavior by
	# diffing against the repository root to produce plumbable
	# output. This is antisocial.
	for(f in `{sort -u <{getfiles $1} <{getfiles $2}}){
		file1=$1/$f; test -f $file1 || file1=/dev/null
		file2=$3/$f; test -f $file2 || file2=/dev/null
		diff $opts $file1 $file2
	}
}
exit ''