view contrib/plan9/9diff @ 26362:3bfc473f4d33

gitweb, monoblue: fix vertical align of spans in .sourcelines

Empty lines in file view could produce an inexplicable margin before the next
line (most noticeable in browsers on webkit/blink engine). That was making
empty lines seem taller than the rest.

Instead of using default vertical align, let's set it to 'top'.

This issue is actually present in paper, and only recently got into gitweb
(2239626369f5) and monoblue (119202d4d7a4). There's a bit more to it in paper,
so that will be dealt with in a future patch.

Recipe to see live: preferably using a webkit/blink browser, such as chromium,
browse a file with empty lines, e.g. https://selenic.com/hg/file/3.5/README#l8
Selecting a block of text that includes empty lines will reveal white "breaks"
in the selection. Highlighted line (#l8) also shows such a break below itself.

#!/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 ''