purge: simplify safety net for case mangling filesystems

Relying on the exact return of statwalk would cause us to abort
when there was at least one tracked file inside an ignored directory.

This patch forces an extra walk of the whole working directory even
on sane filesystems, where it wouldn't be needed.

Fixes issue621.

hgext/purge.py

@@ -1,167 +1,152 b''
 # Copyright (C) 2006 - Marco Barisione <[e-mail]>
 #
 # This is a small extension for Mercurial (http://www.selenic.com/mercurial)
 # that removes files not known to mercurial
 #
 # This program was inspired by the "cvspurge" script contained in CVS utilities
 # (http://www.red-bean.com/cvsutils/).
 #
 # To enable the "purge" extension put these lines in your ~/.hgrc:
 #  [extensions]
 #  hgext.purge =
 #
 # For help on the usage of "hg purge" use:
 #  hg help purge
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
 # the Free Software Foundation; either version 2 of the License, or
 # (at your option) any later version.
 #
 # This program is distributed in the hope that it will be useful,
 # but WITHOUT ANY WARRANTY; without even the implied warranty of
 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 # GNU General Public License for more details.
 #
 # You should have received a copy of the GNU General Public License
 # along with this program; if not, write to the Free Software
 # Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 
 from mercurial import hg, util, commands
 from mercurial.i18n import _
 import os
 
 def dopurge(ui, repo, dirs=None, act=True, ignored=False,
             abort_on_err=False, eol='\n',
             force=False, include=None, exclude=None):
     def error(msg):
         if abort_on_err:
             raise util.Abort(msg)
         else:
             ui.warn(_('warning: %s\n') % msg)
 
     def remove(remove_func, name):
         if act:
             try:
                 remove_func(os.path.join(repo.root, name))
             except OSError, e:
                 error(_('%s cannot be removed') % name)
         else:
             ui.write('%s%s' % (name, eol))
 
+    if not force:
+        _check_fs(ui, repo)
+
     directories = []
     files = []
     missing = []
     roots, match, anypats = util.cmdmatcher(repo.root, repo.getcwd(), dirs,
                                             include, exclude)
     for src, f, st in repo.dirstate.statwalk(files=roots, match=match,
                                              ignored=ignored, directories=True):
         if src == 'd':
             directories.append(f)
         elif src == 'm':
             missing.append(f)
         elif src == 'f' and f not in repo.dirstate:
             files.append(f)
 
-    _check_missing(ui, repo, missing, force)
-
     directories.sort()
 
     for f in files:
         if f not in repo.dirstate:
             ui.note(_('Removing file %s\n') % f)
             remove(os.remove, f)
 
     for f in directories[::-1]:
         if match(f) and not os.listdir(repo.wjoin(f)):
             ui.note(_('Removing directory %s\n') % f)
             remove(os.rmdir, f)
 
-def _check_missing(ui, repo, missing, force=False):
+def _check_fs(ui, repo):
     """Abort if there is the chance of having problems with name-mangling fs
 
     In a name mangling filesystem (e.g. a case insensitive one)
     dirstate.walk() can yield filenames different from the ones
     stored in the dirstate. This already confuses the status and
     add commands, but with purge this may cause data loss.
 
-    To prevent this, _check_missing will abort if there are missing
-    files. The force option will let the user skip the check if he
-    knows it is safe.
-
-    Even with the force option this function will check if any of the
-    missing files is still available in the working dir: if so there
-    may be some problem with the underlying filesystem, so it
-    aborts unconditionally."""
-
-    found = [f for f in missing if util.lexists(repo.wjoin(f))]
+    To prevent this, this function will abort if there are uncommitted
+    changes.
+    """
 
-    if found:
-        if not ui.quiet:
-            ui.warn(_("The following tracked files weren't listed by the "
-                      "filesystem, but could still be found:\n"))
-            for f in found:
-                ui.warn("%s\n" % f)
-            if util.checkfolding(repo.path):
-                ui.warn(_("This is probably due to a case-insensitive "
-                          "filesystem\n"))
-        raise util.Abort(_("purging on name mangling filesystems is not "
-                           "yet fully supported"))
-
-    if missing and not force:
-        raise util.Abort(_("there are missing files in the working dir and "
-                           "purge still has problems with them due to name "
-                           "mangling filesystems. "
-                           "Use --force if you know what you are doing"))
+    # We can't use (files, match) to do a partial walk here - we wouldn't
+    # notice a modified README file if the user ran "hg purge readme"
+    modified, added, removed, deleted = repo.status()[:4]
+    if modified or added or removed or deleted:
+        if not util.checkfolding(repo.path) and not ui.quiet:
+            ui.warn(_("Purging on name mangling filesystems is not "
+                      "fully supported.\n"))
+        raise util.Abort(_("outstanding uncommitted changes"))
 
 
 def purge(ui, repo, *dirs, **opts):
     '''removes files not tracked by mercurial
 
     Delete files not known to mercurial, this is useful to test local and
     uncommitted changes in the otherwise clean source tree.
 
     This means that purge will delete:
      - Unknown files: files marked with "?" by "hg status"
      - Ignored files: files usually ignored by Mercurial because they match
        a pattern in a ".hgignore" file
      - Empty directories: in fact Mercurial ignores directories unless they
        contain files under source control managment
     But it will leave untouched:
      - Unmodified tracked files
      - Modified tracked files
      - New files added to the repository (with "hg add")
 
     If directories are given on the command line, only files in these
     directories are considered.
 
     Be careful with purge, you could irreversibly delete some files you
     forgot to add to the repository. If you only want to print the list of
     files that this program would delete use the --print option.
     '''
     act = not opts['print']
     ignored = bool(opts['all'])
     abort_on_err = bool(opts['abort_on_err'])
     eol = opts['print0'] and '\0' or '\n'
     if eol == '\0':
         # --print0 implies --print
         act = False
     force = bool(opts['force'])
     include = opts['include']
     exclude = opts['exclude']
     dopurge(ui, repo, dirs, act, ignored, abort_on_err,
             eol, force, include, exclude)
 
 
 cmdtable = {
     'purge|clean':
         (purge,
          [('a', 'abort-on-err', None, _('abort if an error occurs')),
           ('',  'all', None, _('purge ignored files too')),
-          ('f', 'force', None, _('purge even when missing files are detected')),
+          ('f', 'force', None, _('purge even when there are uncommitted changes')),
           ('p', 'print', None, _('print the file names instead of deleting them')),
           ('0', 'print0', None, _('end filenames with NUL, for use with xargs'
                                   ' (implies -p)')),
          ] + commands.walkopts,
          _('hg purge [OPTION]... [DIR]...'))
 }

tests/test-purge

@@ -1,133 +1,140 b''
 #!/bin/sh
 
 cat <<EOF >> $HGRCPATH
 [extensions]
 hgext.purge=
 EOF
 
 echo % init
 hg init t
 cd t
 
 echo % setup
 echo r1 > r1
 hg ci -qAmr1 -d'0 0'
 mkdir directory
 echo r2 > directory/r2
 hg ci -qAmr2 -d'1 0'
 echo 'ignored' > .hgignore
 hg ci -qAmr3 -d'2 0'
 
 echo % delete an empty directory
 mkdir empty_dir
 hg purge -p
 hg purge -v
 ls
 
 echo % delete an untracked directory
 mkdir untracked_dir
 touch untracked_dir/untracked_file1
 touch untracked_dir/untracked_file2
 hg purge -p
 hg purge -v
 ls
 
 echo % delete an untracked file
 touch untracked_file
 hg purge -p
 hg purge -v
 ls
 
 echo % delete an untracked file in a tracked directory
 touch directory/untracked_file
 hg purge -p
 hg purge -v
 ls
 
 echo % delete nested directories
 mkdir -p untracked_directory/nested_directory
 hg purge -p
 hg purge -v
 ls
 
 echo % delete nested directories from a subdir
 mkdir -p untracked_directory/nested_directory
 cd directory
 hg purge -p
 hg purge -v
 cd ..
 ls
 
 echo % delete only part of the tree
 mkdir -p untracked_directory/nested_directory
 touch directory/untracked_file
 cd directory
 hg purge -p ../untracked_directory
 hg purge -v ../untracked_directory
 cd ..
 ls
 ls directory/untracked_file
 rm directory/untracked_file
 
 echo % skip ignored files if --all not specified
 touch ignored
 hg purge -p
 hg purge -v
 ls
 hg purge -p --all
 hg purge -v --all
 ls
 
 echo % abort with missing files until we support name mangling filesystems
 touch untracked_file
 rm r1
 # hide error messages to avoid changing the output when the text changes
 hg purge -p 2> /dev/null
 if [ $? -ne 0 ]; then
     echo "refused to run"
 fi
 if [ -f untracked_file ]; then
     echo "untracked_file still around"
 fi
 hg purge -p --force
 hg purge -v 2> /dev/null
 if [ $? -ne 0 ]; then
     echo "refused to run"
 fi
 if [ -f untracked_file ]; then
     echo "untracked_file still around"
 fi
 hg purge -v --force
 hg revert --all --quiet
 ls
 
+echo '% tracked file in ignored directory (issue621)'
+echo directory >> .hgignore
+hg ci -m 'ignore directory'
+touch untracked_file
+hg purge -p
+hg purge -v
+
 echo % skip excluded files
 touch excluded_file
 hg purge -p -X excluded_file
 hg purge -v -X excluded_file
 ls
 rm excluded_file
 
 echo % skip files in excluded dirs
 mkdir excluded_dir
 touch excluded_dir/file
 hg purge -p -X excluded_dir
 hg purge -v -X excluded_dir
 ls
 ls excluded_dir
 rm -R excluded_dir
 
 echo % skip excluded empty dirs
 mkdir excluded_dir
 hg purge -p -X excluded_dir
 hg purge -v -X excluded_dir
 ls
 rmdir excluded_dir
 
 echo % skip patterns
 mkdir .svn
 touch .svn/foo
 mkdir directory/.svn
 touch directory/.svn/foo
 hg purge -p -X .svn -X '*/.svn'
 hg purge -p -X re:.*.svn

tests/test-purge.out

@@ -1,75 +1,78 b''
 % init
 % setup
 % delete an empty directory
 empty_dir
 Removing directory empty_dir
 directory
 r1
 % delete an untracked directory
 untracked_dir/untracked_file1
 untracked_dir/untracked_file2
 Removing file untracked_dir/untracked_file1
 Removing file untracked_dir/untracked_file2
 Removing directory untracked_dir
 directory
 r1
 % delete an untracked file
 untracked_file
 Removing file untracked_file
 directory
 r1
 % delete an untracked file in a tracked directory
 directory/untracked_file
 Removing file directory/untracked_file
 directory
 r1
 % delete nested directories
 untracked_directory/nested_directory
 Removing directory untracked_directory/nested_directory
 Removing directory untracked_directory
 directory
 r1
 % delete nested directories from a subdir
 untracked_directory/nested_directory
 Removing directory untracked_directory/nested_directory
 Removing directory untracked_directory
 directory
 r1
 % delete only part of the tree
 untracked_directory/nested_directory
 Removing directory untracked_directory/nested_directory
 Removing directory untracked_directory
 directory
 r1
 directory/untracked_file
 % skip ignored files if --all not specified
 directory
 ignored
 r1
 ignored
 Removing file ignored
 directory
 r1
 % abort with missing files until we support name mangling filesystems
 refused to run
 untracked_file still around
 untracked_file
 refused to run
 untracked_file still around
 Removing file untracked_file
 directory
 r1
+% tracked file in ignored directory (issue621)
+untracked_file
+Removing file untracked_file
 % skip excluded files
 directory
 excluded_file
 r1
 % skip files in excluded dirs
 directory
 excluded_dir
 r1
 file
 % skip excluded empty dirs
 directory
 excluded_dir
 r1
 % skip patterns