# HG changeset patch
# User Pierre-Yves David <pierre-yves.david@fb.com>
# Date 2015-01-17 02:34:14
# Node ID d251da5e0e841971cc54f2fc1fc4d70743056b5c
# Parent  426607be9c6960588b66e24548dd3cdc8c69d18c

transaction: include backup file in the "undo" transaction

Once the transaction is closed, we now write transaction related data for
possible future undo. For now, we only do it for full file "backup" because
their were not handle at all in that case. In the future, we could move all the
current logic to set undo up (that currently exists in localrepository) inside
transaction itself, but it is not strictly requires to solve the current
situation.

diff --git a/mercurial/transaction.py b/mercurial/transaction.py
--- a/mercurial/transaction.py
+++ b/mercurial/transaction.py
@@ -405,6 +405,7 @@ class transaction(object):
                     self.report("couldn't remote %s: %s\n"
                                 % (vfs.join(b), inst))
         self.entries = []
+        self._writeundo()
         if self.after:
             self.after()
         if self.opener.isfile(self.journal):
@@ -440,6 +441,32 @@ class transaction(object):
         scope)'''
         self._abort()
 
+    def _writeundo(self):
+        """write transaction data for possible future undo call"""
+        if self.undoname is None:
+            return
+        undobackupfile = self.opener.open("%s.backupfiles" % self.undoname, 'w')
+        undobackupfile.write('%d\n' % version)
+        for l, f, b, c in self._backupentries:
+            if not f:  # temporary file
+                continue
+            if not b:
+                u = ''
+            else:
+                if l not in self._vfsmap and c:
+                    self.report("couldn't remote %s: unknown cache location"
+                                "%s\n" % (b, l))
+                    continue
+                vfs = self._vfsmap[l]
+                base, name = vfs.split(b)
+                assert name.startswith(self.journal), name
+                uname = name.replace(self.journal, self.undoname, 1)
+                u = vfs.reljoin(base, uname)
+                util.copyfile(vfs.join(b), vfs.join(u), hardlink=True)
+            undobackupfile.write("%s\0%s\0%s\0%d\n" % (l, f, u, c))
+        undobackupfile.close()
+
+
     def _abort(self):
         self.count = 0
         self.usages = 0
diff --git a/tests/test-fncache.t b/tests/test-fncache.t
--- a/tests/test-fncache.t
+++ b/tests/test-fncache.t
@@ -81,6 +81,7 @@ Non store repo:
   .hg/phaseroots
   .hg/requires
   .hg/undo
+  .hg/undo.backupfiles
   .hg/undo.bookmarks
   .hg/undo.branch
   .hg/undo.desc
@@ -114,6 +115,7 @@ Non fncache repo:
   .hg/store/data/tst.d.hg/_foo.i
   .hg/store/phaseroots
   .hg/store/undo
+  .hg/store/undo.backupfiles
   .hg/store/undo.phaseroots
   .hg/undo.bookmarks
   .hg/undo.branch
diff --git a/tests/test-hardlinks.t b/tests/test-hardlinks.t
--- a/tests/test-hardlinks.t
+++ b/tests/test-hardlinks.t
@@ -50,6 +50,8 @@ Prepare repo r1:
   1 r1/.hg/store/fncache
   1 r1/.hg/store/phaseroots
   1 r1/.hg/store/undo
+  1 r1/.hg/store/undo.backup.fncache
+  1 r1/.hg/store/undo.backupfiles
   1 r1/.hg/store/undo.phaseroots
 
 
@@ -80,6 +82,8 @@ Repos r1 and r2 should now contain hardl
   2 r1/.hg/store/fncache
   1 r1/.hg/store/phaseroots
   1 r1/.hg/store/undo
+  1 r1/.hg/store/undo.backup.fncache
+  1 r1/.hg/store/undo.backupfiles
   1 r1/.hg/store/undo.phaseroots
 
   $ nlinksdir r2/.hg/store
@@ -99,6 +103,7 @@ Repo r3 should not be hardlinked:
   1 r3/.hg/store/fncache
   1 r3/.hg/store/phaseroots
   1 r3/.hg/store/undo
+  1 r3/.hg/store/undo.backupfiles
   1 r3/.hg/store/undo.phaseroots
 
 
@@ -124,6 +129,9 @@ Create a non-inlined filelog in r3:
   1 r3/.hg/store/fncache
   1 r3/.hg/store/phaseroots
   1 r3/.hg/store/undo
+  1 r3/.hg/store/undo.backup.fncache
+  1 r3/.hg/store/undo.backup.phaseroots
+  1 r3/.hg/store/undo.backupfiles
   1 r3/.hg/store/undo.phaseroots
 
 Push to repo r1 should break up most hardlinks in r2:
@@ -151,7 +159,7 @@ Push to repo r1 should break up most har
   1 r2/.hg/store/00manifest.i
   1 r2/.hg/store/data/d1/f2.i
   2 r2/.hg/store/data/f1.i
-  1 r2/.hg/store/fncache
+  2 r2/.hg/store/fncache
 
   $ hg -R r2 verify
   checking changesets
@@ -176,7 +184,7 @@ Committing a change to f1 in r1 must bre
   1 r2/.hg/store/00manifest.i
   1 r2/.hg/store/data/d1/f2.i
   1 r2/.hg/store/data/f1.i
-  1 r2/.hg/store/fncache
+  2 r2/.hg/store/fncache
 
 
   $ cd r3
@@ -210,6 +218,9 @@ r4 has hardlinks in the working dir (not
   2 r4/.hg/store/fncache
   2 r4/.hg/store/phaseroots
   2 r4/.hg/store/undo
+  2 r4/.hg/store/undo.backup.fncache
+  2 r4/.hg/store/undo.backup.phaseroots
+  2 r4/.hg/store/undo.backupfiles
   2 r4/.hg/store/undo.phaseroots
   2 r4/.hg/undo.bookmarks
   2 r4/.hg/undo.branch
@@ -242,6 +253,9 @@ Update back to revision 11 in r4 should 
   2 r4/.hg/store/fncache
   2 r4/.hg/store/phaseroots
   2 r4/.hg/store/undo
+  2 r4/.hg/store/undo.backup.fncache
+  2 r4/.hg/store/undo.backup.phaseroots
+  2 r4/.hg/store/undo.backupfiles
   2 r4/.hg/store/undo.phaseroots
   2 r4/.hg/undo.bookmarks
   2 r4/.hg/undo.branch
diff --git a/tests/test-hook.t b/tests/test-hook.t
--- a/tests/test-hook.t
+++ b/tests/test-hook.t
@@ -158,6 +158,8 @@ more there after
   journal.phaseroots
   phaseroots
   undo
+  undo.backup.fncache
+  undo.backupfiles
   undo.phaseroots
 
 
diff --git a/tests/test-inherit-mode.t b/tests/test-inherit-mode.t
--- a/tests/test-inherit-mode.t
+++ b/tests/test-inherit-mode.t
@@ -81,6 +81,7 @@ new directories are setgid
   00660 ./.hg/store/fncache
   00660 ./.hg/store/phaseroots
   00660 ./.hg/store/undo
+  00660 ./.hg/store/undo.backupfiles
   00660 ./.hg/store/undo.phaseroots
   00660 ./.hg/undo.bookmarks
   00660 ./.hg/undo.branch
@@ -125,6 +126,7 @@ group can still write everything
   00660 ../push/.hg/store/data/foo.i
   00660 ../push/.hg/store/fncache
   00660 ../push/.hg/store/undo
+  00660 ../push/.hg/store/undo.backupfiles
   00660 ../push/.hg/store/undo.phaseroots
   00660 ../push/.hg/undo.bookmarks
   00660 ../push/.hg/undo.branch