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" execbit || exit 80
$ rm -rf a
$ hg init a
$ cd a
$ echo foo > foo
$ hg ci -qAm0
$ chmod +x foo
$ hg ci -m1
$ hg co -q 0
$ echo dirty > foo
$ hg up -c
abort: uncommitted local changes
[255]
$ hg up -q
$ cat foo
dirty
$ hg st -A
M foo
Validate update of standalone execute bit change:
$ hg up -C 0
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ chmod -x foo
$ hg ci -m removeexec
nothing changed
[1]
$ hg up -C 0
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg up
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg st