# HG changeset patch
# User Durham Goode <durham@fb.com>
# Date 2014-10-21 19:38:28
# Node ID 963f311e3a81aafff0835dffdcc7d244e70639c6
# Parent  5dc888b79e7061d7915abd84097243ada21467e8

transactions: change backupfiles format to use newlines

Previously the journal.backupfiles file was delimited by \0. Now we delimit it
using \n (same as the journal file). This allows us to change the number of
values in each line more easily, rather than relying on the count of \0's.

diff --git a/mercurial/transaction.py b/mercurial/transaction.py
--- a/mercurial/transaction.py
+++ b/mercurial/transaction.py
@@ -128,7 +128,7 @@ class transaction(object):
         self.file.write(d)
         self.file.flush()
 
-        d = ''.join(['%s\0%s\0' % (f, b) for f, b in backups])
+        d = ''.join(['%s\0%s\n' % (f, b) for f, b in backups])
         self.backupsfile.write(d)
         self.backupsfile.flush()
 
@@ -177,7 +177,7 @@ class transaction(object):
 
         self.backupentries.append((file, backupfile, None))
         self.backupmap[file] = len(self.backupentries) - 1
-        self.backupsfile.write("%s\0%s\0" % (file, backupfile))
+        self.backupsfile.write("%s\0%s\n" % (file, backupfile))
         self.backupsfile.flush()
 
     @active
@@ -349,20 +349,16 @@ def rollback(opener, file, report):
     backupjournal = "%s.backupfiles" % file
     if opener.exists(backupjournal):
         fp = opener.open(backupjournal)
-        data = fp.read()
-        if len(data) > 0:
-            ver = version
-            versionend = data.find('\n')
-            if versionend != -1:
-                ver = data[:versionend]
-                data = data[versionend + 1:]
-
+        lines = fp.readlines()
+        if lines:
+            ver = lines[0][:-1]
             if ver == str(version):
-                parts = data.split('\0')
-                # Skip the final part, since it's just a trailing empty space
-                for i in xrange(0, len(parts) - 1, 2):
-                    f, b = parts[i:i + 2]
-                    backupentries.append((f, b, None))
+                for line in lines[1:]:
+                    if line:
+                        # Shave off the trailing newline
+                        line = line[:-1]
+                        f, b = line.split('\0')
+                        backupentries.append((f, b, None))
             else:
                 report(_("journal was created by a newer version of "
                          "Mercurial"))