revert does not preserve executable bit

[John Dong]

Revert doesn't care about the executable bit, and can even inadvertently strip it off.

TO REPRODUCE:
jdong@jdong-laptop:/tmp$ bzr init test
jdong@jdong-laptop:/tmp$ cd test
jdong@jdong-laptop:/tmp/test$ echo a > a
jdong@jdong-laptop:/tmp/test$ chmod +x a
jdong@jdong-laptop:/tmp/test$ bzr add && bzr ci -m a
added a
added a
Committed revision 1.
jdong@jdong-laptop:/tmp/test$ ls -l a
-rwxr-xr-x 1 jdong jdong 2 2006-12-06 15:32 a
jdong@jdong-laptop:/tmp/test$

So, a branch with a single file (executable) named a. Now, here's where the bug takes place:

jdong@jdong-laptop:/tmp/test$ echo b > a
jdong@jdong-laptop:/tmp/test$ ls -l a
-rwxr-xr-x 1 jdong jdong 2 2006-12-06 15:33 a
jdong@jdong-laptop:/tmp/test$ bzr st
modified:
  a
jdong@jdong-laptop:/tmp/test$ bzr revert
jdong@jdong-laptop:/tmp/test$ ls -al
total 20
drwxr-xr-x 3 jdong jdong 4096 2006-12-06 15:34 .
drwxrwxrwt 11 root root 4096 2006-12-06 15:32 ..
-rw-r--r-- 1 jdong jdong 2 2006-12-06 15:34 a
-rwxr-xr-x 1 jdong jdong 2 2006-12-06 15:33 a.~1~
drwxr-xr-x 6 jdong jdong 4096 2006-12-06 15:32 .bzr
jdong@jdong-laptop:/tmp/test$ bzr st
modified:
  a*
jdong@jdong-laptop:/tmp/test$ bzr revert
jdong@jdong-laptop:/tmp/test$ bzr st
modified:
  a*

After changing a then running a revert, the executable bit disappears from a. Further reverts do not fix it.

[John Dong (jdong)]

This is on Linux with the latest bzr.dev, btw.

[John A Meinel (jameinel)]

I can also confirm that doing:
$ echo a > a; chmod +x a
$ bzr add ; bzr commit -m a
$ chmod -x a
$ bzr status
modified:
  a*

$ bzr revert
$ bzr status
modified:
  a*

So if the only change is the executable bit, 'bzr revert' isn't fixing it.

[John A Meinel (jameinel)]

Aaron introduced and fixed the bug in bzr.dev post bzr 0.13