bdiff: fix malloc(0) issue in fixws()
If fixws() is called on a zero-length string, malloc(0) is called and
expected to return a pointer. Which it does on e.g. Linux. AIX returns
NULL, which it is also legal, but the malloc() is then assumed to have
failed. So ensure a valid pointer is always returned.
$ "$TESTDIR/hghave" symlink || exit 80
$ hg init
should fail
$ hg add .hg/00changelog.i
abort: path contains illegal component: .hg/00changelog.i (glob)
[255]
$ mkdir a
$ echo a > a/a
$ hg ci -Ama
adding a/a
$ ln -s a b
$ echo b > a/b
should fail
$ hg add b/b
abort: path 'b/b' traverses symbolic link 'b' (glob)
[255]
should succeed
$ hg add b
should still fail - maybe
$ hg add b/b
abort: path 'b/b' traverses symbolic link 'b' (glob)
[255]
unbundle tampered bundle
$ hg init target
$ cd target
$ hg unbundle $TESTDIR/bundles/tampered.hg
adding changesets
adding manifests
adding file changes
added 5 changesets with 6 changes to 6 files (+4 heads)
(run 'hg heads' to see heads, 'hg merge' to merge)
attack .hg/test
$ hg manifest -r0
.hg/test
$ hg update -Cr0
abort: path contains illegal component: .hg/test
[255]
attack foo/.hg/test
$ hg manifest -r1
foo/.hg/test
$ hg update -Cr1
abort: path 'foo/.hg/test' is inside nested repo 'foo'
[255]
attack back/test where back symlinks to ..
$ hg manifest -r2
back
back/test
$ hg update -Cr2
abort: path 'back/test' traverses symbolic link 'back'
[255]
attack ../test
$ hg manifest -r3
../test
$ hg update -Cr3
abort: path contains illegal component: ../test
[255]
attack /tmp/test
$ hg manifest -r4
/tmp/test
$ hg update -Cr4
abort: *: $TESTTMP/target//tmp/test (glob)
[255]