repair: forbid strip from inside a transaction

Stripping inside a transaction will (at best) crash or (at worst)
result in very unexpected results. We explicitly forbid it early.

mercurial/repair.py

@@ -1,225 +1,231 b''
 # repair.py - functions for repository repair for mercurial
 #
 # Copyright 2005, 2006 Chris Mason <[e-mail]>
 # Copyright 2007 Matt Mackall
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 from mercurial import changegroup, exchange, util, bundle2
 from mercurial.node import short, hex
 from mercurial.i18n import _
 import errno
 
 def _bundle(repo, bases, heads, node, suffix, compress=True):
     """create a bundle with the specified revisions as a backup"""
     usebundle2 = (repo.ui.config('experimental', 'bundle2-exp') and
                   repo.ui.config('experimental', 'strip-bundle2-version'))
     if usebundle2:
         cgversion = repo.ui.config('experimental', 'strip-bundle2-version')
         if cgversion not in changegroup.packermap:
             repo.ui.warn(_('unknown strip-bundle2-version value %r; '
                             'should be one of %r\n') %
                          (cgversion, sorted(changegroup.packermap.keys()),))
             cgversion = '01'
             usebundle2 = False
     else:
         cgversion = '01'
 
     cg = changegroup.changegroupsubset(repo, bases, heads, 'strip',
                                        version=cgversion)
     backupdir = "strip-backup"
     vfs = repo.vfs
     if not vfs.isdir(backupdir):
         vfs.mkdir(backupdir)
 
     # Include a hash of all the nodes in the filename for uniqueness
     hexbases = (hex(n) for n in bases)
     hexheads = (hex(n) for n in heads)
     allcommits = repo.set('%ls::%ls', hexbases, hexheads)
     allhashes = sorted(c.hex() for c in allcommits)
     totalhash = util.sha1(''.join(allhashes)).hexdigest()
     name = "%s/%s-%s-%s.hg" % (backupdir, short(node), totalhash[:8], suffix)
 
     if usebundle2:
         bundletype = "HG20"
     elif compress:
         bundletype = "HG10BZ"
     else:
         bundletype = "HG10UN"
     return changegroup.writebundle(repo.ui, cg, name, bundletype, vfs)
 
 def _collectfiles(repo, striprev):
     """find out the filelogs affected by the strip"""
     files = set()
 
     for x in xrange(striprev, len(repo)):
         files.update(repo[x].files())
 
     return sorted(files)
 
 def _collectbrokencsets(repo, files, striprev):
     """return the changesets which will be broken by the truncation"""
     s = set()
     def collectone(revlog):
         _, brokenset = revlog.getstrippoint(striprev)
         s.update([revlog.linkrev(r) for r in brokenset])
 
     collectone(repo.manifest)
     for fname in files:
         collectone(repo.file(fname))
 
     return s
 
 def strip(ui, repo, nodelist, backup=True, topic='backup'):
 
     # Simple way to maintain backwards compatibility for this
     # argument.
     if backup in ['none', 'strip']:
         backup = False
 
     repo = repo.unfiltered()
     repo.destroying()
 
     cl = repo.changelog
     # TODO handle undo of merge sets
     if isinstance(nodelist, str):
         nodelist = [nodelist]
     striplist = [cl.rev(node) for node in nodelist]
     striprev = min(striplist)
 
     # Some revisions with rev > striprev may not be descendants of striprev.
     # We have to find these revisions and put them in a bundle, so that
     # we can restore them after the truncations.
     # To create the bundle we use repo.changegroupsubset which requires
     # the list of heads and bases of the set of interesting revisions.
     # (head = revision in the set that has no descendant in the set;
     #  base = revision in the set that has no ancestor in the set)
     tostrip = set(striplist)
     for rev in striplist:
         for desc in cl.descendants([rev]):
             tostrip.add(desc)
 
     files = _collectfiles(repo, striprev)
     saverevs = _collectbrokencsets(repo, files, striprev)
 
     # compute heads
     saveheads = set(saverevs)
     for r in xrange(striprev + 1, len(cl)):
         if r not in tostrip:
             saverevs.add(r)
             saveheads.difference_update(cl.parentrevs(r))
             saveheads.add(r)
     saveheads = [cl.node(r) for r in saveheads]
 
     # compute base nodes
     if saverevs:
         descendants = set(cl.descendants(saverevs))
         saverevs.difference_update(descendants)
     savebases = [cl.node(r) for r in saverevs]
     stripbases = [cl.node(r) for r in tostrip]
 
     # For a set s, max(parents(s) - s) is the same as max(heads(::s - s)), but
     # is much faster
     newbmtarget = repo.revs('max(parents(%ld) - (%ld))', tostrip, tostrip)
     if newbmtarget:
         newbmtarget = repo[newbmtarget.first()].node()
     else:
         newbmtarget = '.'
 
     bm = repo._bookmarks
     updatebm = []
     for m in bm:
         rev = repo[bm[m]].rev()
         if rev in tostrip:
             updatebm.append(m)
 
     # create a changegroup for all the branches we need to keep
     backupfile = None
     vfs = repo.vfs
     node = nodelist[-1]
     if backup:
         backupfile = _bundle(repo, stripbases, cl.heads(), node, topic)
         repo.ui.status(_("saved backup bundle to %s\n") %
                        vfs.join(backupfile))
         repo.ui.log("backupbundle", "saved backup bundle to %s\n",
                     vfs.join(backupfile))
     if saveheads or savebases:
         # do not compress partial bundle if we remove it from disk later
         chgrpfile = _bundle(repo, savebases, saveheads, node, 'temp',
                             compress=False)
 
     mfst = repo.manifest
 
+    curtr = repo.currenttransaction()
+    if curtr is not None:
+        del curtr  # avoid carrying reference to transaction for nothing
+        msg = _('programming error: cannot strip from inside a transaction')
+        raise util.Abort(msg, hint=_('contact your extension maintainer'))
+
     tr = repo.transaction("strip")
     offset = len(tr.entries)
 
     try:
         tr.startgroup()
         cl.strip(striprev, tr)
         mfst.strip(striprev, tr)
         for fn in files:
             repo.file(fn).strip(striprev, tr)
         tr.endgroup()
 
         try:
             for i in xrange(offset, len(tr.entries)):
                 file, troffset, ignore = tr.entries[i]
                 repo.svfs(file, 'a').truncate(troffset)
                 if troffset == 0:
                     repo.store.markremoved(file)
             tr.close()
         except: # re-raises
             tr.abort()
             raise
 
         if saveheads or savebases:
             ui.note(_("adding branch\n"))
             f = vfs.open(chgrpfile, "rb")
             gen = exchange.readbundle(ui, f, chgrpfile, vfs)
             if not repo.ui.verbose:
                 # silence internal shuffling chatter
                 repo.ui.pushbuffer()
             if isinstance(gen, bundle2.unbundle20):
                 tr = repo.transaction('strip')
                 tr.hookargs = {'source': 'strip',
                                'url': 'bundle:' + vfs.join(chgrpfile)}
                 try:
                     bundle2.processbundle(repo, gen, lambda: tr)
                     tr.close()
                 finally:
                     tr.release()
             else:
                 changegroup.addchangegroup(repo, gen, 'strip',
                                            'bundle:' + vfs.join(chgrpfile),
                                            True)
             if not repo.ui.verbose:
                 repo.ui.popbuffer()
             f.close()
 
         # remove undo files
         for undovfs, undofile in repo.undofiles():
             try:
                 undovfs.unlink(undofile)
             except OSError, e:
                 if e.errno != errno.ENOENT:
                     ui.warn(_('error removing %s: %s\n') %
                             (undovfs.join(undofile), str(e)))
 
         for m in updatebm:
             bm[m] = repo[newbmtarget].node()
         bm.write()
     except: # re-raises
         if backupfile:
             ui.warn(_("strip failed, full bundle stored in '%s'\n")
                     % vfs.join(backupfile))
         elif saveheads:
             ui.warn(_("strip failed, partial bundle stored in '%s'\n")
                     % vfs.join(chgrpfile))
         raise
     else:
         if saveheads or savebases:
             # Remove partial backup only if there were no exceptions
             vfs.unlink(chgrpfile)
 
     repo.destroyed()

tests/test-devel-warnings.t

@@ -1,90 +1,109 b''
 
   $ cat << EOF > buggylocking.py
   > """A small extension that acquire locks in the wrong order
   > """
   > 
-  > from mercurial import cmdutil
+  > from mercurial import cmdutil, repair
   > 
   > cmdtable = {}
   > command = cmdutil.command(cmdtable)
   > 
   > @command('buggylocking', [], '')
   > def buggylocking(ui, repo):
   >     tr = repo.transaction('buggy')
   >     lo = repo.lock()
   >     wl = repo.wlock()
   >     wl.release()
   >     lo.release()
   > 
   > @command('properlocking', [], '')
   > def properlocking(ui, repo):
   >     """check that reentrance is fine"""
   >     wl = repo.wlock()
   >     lo = repo.lock()
   >     tr = repo.transaction('proper')
   >     tr2 = repo.transaction('proper')
   >     lo2 = repo.lock()
   >     wl2 = repo.wlock()
   >     wl2.release()
   >     lo2.release()
   >     tr2.close()
   >     tr.close()
   >     lo.release()
   >     wl.release()
   > 
   > @command('nowaitlocking', [], '')
   > def nowaitlocking(ui, repo):
   >     lo = repo.lock()
   >     wl = repo.wlock(wait=False)
   >     wl.release()
   >     lo.release()
+  > 
+  > @command('stripintr', [], '')
+  > def stripintr(ui, repo):
+  >     lo = repo.lock()
+  >     tr = repo.transaction('foobar')
+  >     try:
+  >         repair.strip(repo.ui, repo, [repo['.'].node()])
+  >     finally:
+  >         lo.release()
   > EOF
 
   $ cat << EOF >> $HGRCPATH
   > [extensions]
   > buggylocking=$TESTTMP/buggylocking.py
   > [devel]
   > all-warnings=1
   > EOF
 
   $ hg init lock-checker
   $ cd lock-checker
   $ hg buggylocking
   devel-warn: transaction with no lock at: $TESTTMP/buggylocking.py:11 (buggylocking)
   devel-warn: "wlock" acquired after "lock" at: $TESTTMP/buggylocking.py:13 (buggylocking)
   $ cat << EOF >> $HGRCPATH
   > [devel]
   > all=0
   > check-locks=1
   > EOF
   $ hg buggylocking
   devel-warn: transaction with no lock at: $TESTTMP/buggylocking.py:11 (buggylocking)
   devel-warn: "wlock" acquired after "lock" at: $TESTTMP/buggylocking.py:13 (buggylocking)
   $ hg buggylocking --traceback
   devel-warn: transaction with no lock at:
    */hg:* in * (glob)
    */mercurial/dispatch.py:* in run (glob)
    */mercurial/dispatch.py:* in dispatch (glob)
    */mercurial/dispatch.py:* in _runcatch (glob)
    */mercurial/dispatch.py:* in _dispatch (glob)
    */mercurial/dispatch.py:* in runcommand (glob)
    */mercurial/dispatch.py:* in _runcommand (glob)
    */mercurial/dispatch.py:* in checkargs (glob)
    */mercurial/dispatch.py:* in <lambda> (glob)
    */mercurial/util.py:* in check (glob)
    $TESTTMP/buggylocking.py:* in buggylocking (glob)
   devel-warn: "wlock" acquired after "lock" at:
    */hg:* in * (glob)
    */mercurial/dispatch.py:* in run (glob)
    */mercurial/dispatch.py:* in dispatch (glob)
    */mercurial/dispatch.py:* in _runcatch (glob)
    */mercurial/dispatch.py:* in _dispatch (glob)
    */mercurial/dispatch.py:* in runcommand (glob)
    */mercurial/dispatch.py:* in _runcommand (glob)
    */mercurial/dispatch.py:* in checkargs (glob)
    */mercurial/dispatch.py:* in <lambda> (glob)
    */mercurial/util.py:* in check (glob)
    $TESTTMP/buggylocking.py:* in buggylocking (glob)
   $ hg properlocking
   $ hg nowaitlocking
+
+  $ echo a > a
+  $ hg add a
+  $ hg commit -m a
+  $ hg stripintr
+  saved backup bundle to $TESTTMP/lock-checker/.hg/strip-backup/cb9a9f314b8b-cc5ccb0b-backup.hg (glob)
+  abort: programming error: cannot strip from inside a transaction
+  (contact your extension maintainer)
+  [255]
+
   $ cd ..