[PATCH] repair: forbid strip from inside a transaction

[Pierre-Yves David]

# HG changeset patch
# User Pierre-Yves David <pierre-yves.david at fb.com>
# Date 1432441127 25200
#      Sat May 23 21:18:47 2015 -0700
# Node ID 0c71ff45e361550948fcc3cbfa03898c8ba9fd96
# Parent  61b3529e23778f542044d24bb1ccd5688516a7f0
repair: forbid strip from inside a transaction

Striping inside a transaction will, at best, crash or , at worst, result in very
unexpected result. We explicitly forbid it early.

diff --git a/mercurial/repair.py b/mercurial/repair.py
--- a/mercurial/repair.py
+++ b/mercurial/repair.py
@@ -149,10 +149,16 @@ def strip(ui, repo, nodelist, backup=Tru
         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 extensions maintainer'))
+
     tr = repo.transaction("strip")
     offset = len(tr.entries)
 
     try:
         tr.startgroup()
diff --git a/tests/test-devel-warnings.t b/tests/test-devel-warnings.t
--- a/tests/test-devel-warnings.t
+++ b/tests/test-devel-warnings.t
@@ -1,11 +1,11 @@
 
   $ 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', [], '')
@@ -36,10 +36,17 @@
   > 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()
+  >     # not a warning no worth testing.
+  >     tr = repo.transaction('foobar')
+  >     repair.strip(repo.ui, repo, [repo['.'].node()])
   > EOF
 
   $ cat << EOF >> $HGRCPATH
   > [extensions]
   > buggylocking=$TESTTMP/buggylocking.py
@@ -85,6 +92,16 @@
    */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 extensions maintainer)
+  [255]
+
   $ cd ..