view tests/test-convert-bzr-treeroot.t @ 24624:6f0e6fa9fdd7

dirs._addpath: don't mutate Python strings after exposing them (issue4589)

One of the rules of Python strings is that they're immutable. dirs._addpath
breaks this assumption for performance, which is fine as long as it is done
safely -- once a string is no longer internal-only it shouldn't be mutated.
Unfortunately, we weren't being safe here -- we were mutating 'key' even after
adding it to a dictionary.

This only really affects other C code that reads strings, so it's somewhat hard
to write a test for this without poking into the internal representation of the
string via ctypes or similar. There is currently no C code that reads the
output of the string, but there will likely be some soon as the bug indicates.

There's no significant difference in performance.

  $ . "$TESTDIR/bzr-definitions"
  $ cat > treeset.py <<EOF
  > import sys
  > from bzrlib import workingtree
  > wt = workingtree.WorkingTree.open('.')
  > 
  > message, rootid = sys.argv[1:]
  > wt.set_root_id('tree_root-%s' % rootid)
  > wt.commit(message)
  > EOF

change the id of the tree root

  $ mkdir test-change-treeroot-id
  $ cd test-change-treeroot-id
  $ bzr init -q source
  $ cd source
  $ echo content > file
  $ bzr add -q file
  $ bzr commit -q -m 'Initial add'
  $ python ../../treeset.py 'Changed root' new
  $ cd ..
  $ hg convert source source-hg
  initializing destination source-hg repository
  scanning source...
  sorting...
  converting...
  1 Initial add
  0 Changed root
  $ manifest source-hg tip
  % manifest of tip
  644   file

  $ cd ..