transaction: only delete journal on successful abort/commit

This solves that the journal file was always deleted when the transaction
was deleted, no matter whether the abort (rollback) succeeded or not.
Thus, never supporting a hg recover. The journal file is now only deleted
on close (commit) or a successful abort.

mercurial/transaction.py

@@ -1,112 +1,118 b''
 # transaction.py - simple journalling scheme for mercurial
 #
 # This transaction scheme is intended to gracefully handle program
 # errors and interruptions. More serious failures like system crashes
 # can be recovered with an fsck-like tool. As the whole repository is
 # effectively log-structured, this should amount to simply truncating
 # anything that isn't referenced in the changelog.
 #
 # Copyright 2005, 2006 Matt Mackall <[e-mail]>
 #
 # This software may be used and distributed according to the terms
 # of the GNU General Public License, incorporated herein by reference.
 
 from i18n import _
 import os, errno
 
 class transaction(object):
     def __init__(self, report, opener, journal, after=None, createmode=None):
         self.journal = None
 
         self.count = 1
         self.report = report
         self.opener = opener
         self.after = after
         self.entries = []
         self.map = {}
         self.journal = journal
 
         self.file = open(self.journal, "w")
         if createmode is not None:
             os.chmod(self.journal, createmode & 0666)
 
     def __del__(self):
         if self.journal:
             if self.entries: self.abort()
             self.file.close()
-            try: os.unlink(self.journal)
-            except: pass
 
     def add(self, file, offset, data=None):
         if file in self.map: return
         self.entries.append((file, offset, data))
         self.map[file] = len(self.entries) - 1
         # add enough data to the journal to do the truncate
         self.file.write("%s\0%d\n" % (file, offset))
         self.file.flush()
 
     def find(self, file):
         if file in self.map:
             return self.entries[self.map[file]]
         return None
 
     def replace(self, file, offset, data=None):
         if file not in self.map:
             raise KeyError(file)
         index = self.map[file]
         self.entries[index] = (file, offset, data)
         self.file.write("%s\0%d\n" % (file, offset))
         self.file.flush()
 
     def nest(self):
         self.count += 1
         return self
 
     def running(self):
         return self.count > 0
 
     def close(self):
         self.count -= 1
         if self.count != 0:
             return
         self.file.close()
         self.entries = []
         if self.after:
             self.after()
         else:
             os.unlink(self.journal)
         self.journal = None
 
     def abort(self):
         if not self.entries: return
 
         self.report(_("transaction abort!\n"))
 
+        failed = False
         for f, o, ignore in self.entries:
             try:
                 self.opener(f, "a").truncate(o)
             except:
+                failed = True
                 self.report(_("failed to truncate %s\n") % f)
 
         self.entries = []
 
+        if not failed:
+            self.file.close()
+            os.unlink(self.journal)
+            self.journal = None
         self.report(_("rollback completed\n"))
+        else:
+            self.report(_("rollback failed - please run hg recover\n"))
 
 def rollback(opener, file):
     files = {}
     for l in open(file).readlines():
         f, o = l.split('\0')
         files[f] = int(o)
     for f in files:
         o = files[f]
         if o:
             opener(f, "a").truncate(int(o))
         else:
             try:
                 fn = opener(f).name
                 os.unlink(fn)
             except OSError, inst:
                 if inst.errno != errno.ENOENT:
                     raise
     os.unlink(file)