subrepo: disallow symlink traversal across subrepo mount point (SEC)
It wasn't easy to extend the pathauditor to check symlink traversal across
subrepos because pathauditor._checkfs() rejects a directory having ".hg"
directory. That's why I added the explicit islink() check.
No idea if this patch is necessary after we've fixed the issue5730 by
splitting submerge() into planning and execution phases.
$ hg init
$ $PYTHON -c 'open("a", "wb").write(b"confuse str.splitlines\nembedded\rnewline\n")'
$ hg ci -Ama -d '1 0'
adding a
$ echo clean diff >> a
$ hg ci -mb -d '2 0'
$ hg diff -r0 -r1
diff -r 107ba6f817b5 -r 310ce7989cdc a
--- a/a Thu Jan 01 00:00:01 1970 +0000
+++ b/a Thu Jan 01 00:00:02 1970 +0000
@@ -1,2 +1,3 @@
confuse str.splitlines
embedded\r (no-eol) (esc)
newline
+clean diff