subrepo: handle svn tracked/unknown directory collisions stable

subrepo: handle svn tracked/unknown directory collisions

This happens more often than expected. Say you have an svn subrepository with
python code. Python would have generated unknown .pyc files. Now, you rebase
this setup on a revision where a directory containing python code does not
exist. Subversion is first asked to remove this directory when updating, but
will not because it contains untracked items. Then it will have to bring back
the directory after the merge but will fail because it now collides with an
untracked directory.

Using --force is not very elegant and only works with svn >= 1.5 but the only
alternative I can think of is to write our own purge command for subversion.

--- a/mercurial/subrepo.py	Fri Apr 29 03:05:48 2011 -0500
+++ b/mercurial/subrepo.py	Fri Mar 04 14:00:49 2011 +0100
@@ -10,6 +10,7 @@
 from i18n import _
 import config, util, node, error, cmdutil
 hg = None
+propertycache = util.propertycache
 
 nullstate = ('', '', 'empty')
 
@@ -521,7 +522,6 @@
         self._ui = ctx._repo.ui
 
     def _svncommand(self, commands, filename=''):
-        path = os.path.join(self._ctx._repo.origroot, self._path, filename)
         cmd = ['svn']
         # Starting in svn 1.5 --non-interactive is a global flag
         # instead of being per-command, but we need to support 1.4 so
@@ -531,7 +531,9 @@
             commands[0] in ('update', 'checkout', 'commit')):
             cmd.append('--non-interactive')
         cmd.extend(commands)
-        cmd.append(path)
+        if filename is not None:
+            path = os.path.join(self._ctx._repo.origroot, self._path, filename)
+            cmd.append(path)
         env = dict(os.environ)
         # Avoid localized output, preserve current locale for everything else.
         env['LC_MESSAGES'] = 'C'
@@ -544,6 +546,14 @@
             raise util.Abort(stderr)
         return stdout
 
+    @propertycache
+    def _svnversion(self):
+        output = self._svncommand(['--version'], filename=None)
+        m = re.search(r'^svn,\s+version\s+(\d+)\.(\d+)', output)
+        if not m:
+            raise util.Abort(_('cannot retrieve svn tool version'))
+        return (int(m.group(1)), int(m.group(2)))
+
     def _wcrevs(self):
         # Get the working directory revision as well as the last
         # commit revision so we can compare the subrepo state with
@@ -638,7 +648,11 @@
     def get(self, state, overwrite=False):
         if overwrite:
             self._svncommand(['revert', '--recursive'])
-        status = self._svncommand(['checkout', state[0], '--revision', state[1]])
+        args = ['checkout']
+        if self._svnversion >= (1, 5):
+            args.append('--force')
+        args.extend([state[0], '--revision', state[1]])
+        status = self._svncommand(args)
         if not re.search('Checked out revision [0-9]+.', status):
             raise util.Abort(status.splitlines()[-1])
         self._ui.status(status)

--- a/tests/hghave	Fri Apr 29 03:05:48 2011 -0500
+++ b/tests/hghave	Fri Mar 04 14:00:49 2011 +0100
@@ -121,6 +121,15 @@
     except ImportError:
         return False
 
+def getsvnversion():
+    m = matchoutput('svn --version 2>&1', r'^svn,\s+version\s+(\d+)\.(\d+)')
+    if not m:
+        return (0, 0)
+    return (int(m.group(1)), int(m.group(2)))
+
+def has_svn15():
+    return getsvnversion() >= (1, 5)
+
 def has_svn():
     return matchoutput('svn --version 2>&1', r'^svn, version') and \
         matchoutput('svnadmin --version 2>&1', r'^svnadmin, version')
@@ -204,6 +213,7 @@
     "pygments": (has_pygments, "Pygments source highlighting library"),
     "ssl": (has_ssl, "python >= 2.6 ssl module and python OpenSSL"),
     "svn": (has_svn, "subversion client and admin tools"),
+    "svn15": (has_svn15, "subversion client and admin tools >= 1.5"),
     "svn-bindings": (has_svn_bindings, "subversion python bindings"),
     "symlink": (has_symlink, "symbolic links"),
     "tla": (has_tla, "GNU Arch tla client"),

--- a/tests/test-subrepo-svn.t	Fri Apr 29 03:05:48 2011 -0500
+++ b/tests/test-subrepo-svn.t	Fri Mar 04 14:00:49 2011 +0100
@@ -438,3 +438,54 @@
   $ svnversion
   2
   $ cd ..
+
+Test case where subversion would fail to update the subrepo because there
+are unknown directories being replaced by tracked ones (happens with rebase).
+
+  $ cd $WCROOT/src
+  $ mkdir dir
+  $ echo epsilon.py > dir/epsilon.py
+  $ svn add dir
+  A         dir
+  A         dir/epsilon.py
+  $ svn ci -m 'Add dir/epsilon.py'
+  Adding         src/dir
+  Adding         src/dir/epsilon.py
+  Transmitting file data .
+  Committed revision 6.
+  $ cd ../..
+  $ hg init rebaserepo
+  $ cd rebaserepo
+  $ svn co -r5 --quiet "$SVNREPO"/src s
+  $ echo "s =        [svn]       $SVNREPO/src" >> .hgsub
+  $ hg add .hgsub
+  $ hg ci -m addsub
+  committing subrepository s
+  $ echo a > a
+  $ hg ci -Am adda
+  adding a
+  $ hg up 0
+  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
+  $ svn up -r6 s
+  A    s/dir
+  A    s/dir/epsilon.py
+  
+  Fetching external item into 's/externals'
+  Updated external to revision 1.
+  
+  Updated to revision 6.
+  $ hg ci -m updatesub
+  committing subrepository s
+  created new head
+  $ echo pyc > s/dir/epsilon.pyc
+  $ hg up 1
+  D    $TESTTMP/rebaserepo/s/dir
+  
+  Fetching external item into '$TESTTMP/rebaserepo/s/externals'
+  Checked out external at revision 1.
+  
+  Checked out revision 5.
+  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  $ if "$TESTDIR/hghave" -q svn15; then
+  > hg up 2 >/dev/null 2>&1 || echo update failed
+  > fi