codehosting server busy-loops when the branch root directory does not exist

[James Henstridge]

I was testing out the codehosting server locally, and had not created the /var/tmp/sm-ng directory. When I tried to push a branch to it via bzr+ssh, I noticed that the "bzr lp-serve" process was using 100% CPU and not appearing to do anything.

Attaching strace to the process, I saw the following four lines repeated over and over:
  futex(0x7c9fd0, FUTEX_WAKE, 1) = 0
  futex(0x7c9fd0, FUTEX_WAKE, 1) = 0
  futex(0x7c9fd0, FUTEX_WAKE, 1) = 0
  mkdir("/var/tmp/sm-ng/push-branches/", 0777) = -1 ENOENT (No such file or directory)

My guess is that the makedirs() implementation is interacting badly with the chroot transport (i.e. "/" doesn't exist, so it tries to create "/.." which is the same as "/", etc).

Creating /var/tmp/sm-ng fixed the problem, but it'd be good to avoid the busy loop.

[Jonathan Lange (jml)]

This bug doesn't occur for me any more.