[PATCH 3 of 3 V2] devel: also warn about transaction started without a lock

[Pierre-Yves David]

# HG changeset patch
# User Pierre-Yves David <pierre-yves.david at fb.com>
# Date 1426046625 25200
#      Tue Mar 10 21:03:45 2015 -0700
# Node ID 89890be5e4d784cb264583b5366d852a5a50561f
# Parent  81e2aeedbed4a8b18dc7d8d3f9d6f8d7eb6d0d24
devel: also warn about transaction started without a lock

Nobody should even start a transaction on an unlocked repository. If developer
warning are enabled this will be reported. This use the same config as the bad
locking order as this is closely related.

diff --git a/mercurial/localrepo.py b/mercurial/localrepo.py
--- a/mercurial/localrepo.py
+++ b/mercurial/localrepo.py
@@ -917,10 +917,19 @@ class localrepository(object):
         if tr and tr.running():
             return tr
         return None
 
     def transaction(self, desc, report=None):
+        if (self.ui.configbool('devel', 'all')
+                or self.ui.configbool('devel', 'check-locks')):
+            l = self._lockref and self._lockref()
+            if l is None or not l.held:
+                msg = 'transaction with no lock\n'
+                if self.ui.tracebackflag:
+                    util.debugstacktrace(msg, 1)
+                else:
+                    self.ui.write_err(msg)
         tr = self.currenttransaction()
         if tr is not None:
             return tr.nest()
 
         # abort here if the journal already exists
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
@@ -8,10 +8,11 @@
   > cmdtable = {}
   > command = cmdutil.command(cmdtable)
   > 
   > @command('buggylocking', [], '')
   > def buggylocking(ui, repo):
+  >     tr = repo.transaction('buggy')
   >     lo = repo.lock()
   >     wl = repo.wlock()
   > EOF
 
   $ cat << EOF >> $HGRCPATH
@@ -22,19 +23,34 @@
   > EOF
 
   $ hg init lock-checker
   $ cd lock-checker
   $ hg buggylocking
+  transaction with no lock
   "lock" taken before "wlock"
   $ cat << EOF >> $HGRCPATH
   > [devel]
   > all=0
   > check-locks=1
   > EOF
   $ hg buggylocking
+  transaction with no lock
   "lock" taken before "wlock"
   $ hg buggylocking --traceback
+  transaction with no lock
+   at:
+   */hg:* in <module> (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)
   "lock" taken before "wlock"
    at:
    */hg:* in <module> (glob)
    */mercurial/dispatch.py:* in run (glob)
    */mercurial/dispatch.py:* in dispatch (glob)