revlog: abort on attempt to write null revision
authorMartin von Zweigbergk <martinvonz@google.com>
Fri, 25 Aug 2017 15:50:07 -0700
changeset 33956 9180f8f593f3
parent 33955 e43264525ce5
child 33957 9d5d040160e6
revlog: abort on attempt to write null revision My repo got corrupted yesterday by something that ended up writing the null revision to the revlog (nullid hash, not nullrev index, of course). We use many extensions internally (narrowhg, remotefilelog, evolve, internal extensions) and treemanifests are on. The null revision was written to the changelog, the root manifest log, and one subdirectory manifest log. I have no idea exactly why the null revision was written, but it seems cheap enough to check that we should fail instead of corrupting the repo. Differential Revision: https://phab.mercurial-scm.org/D522
mercurial/revlog.py
--- a/mercurial/revlog.py	Tue Aug 22 23:39:05 2017 -0700
+++ b/mercurial/revlog.py	Fri Aug 25 15:50:07 2017 -0700
@@ -1694,6 +1694,9 @@
         - rawtext is optional (can be None); if not set, cachedelta must be set.
           if both are set, they must correspond to each other.
         """
+        if node == nullid:
+            raise RevlogError(_("%s: attempt to add null revision") %
+                              (self.indexfile))
         btext = [rawtext]
         def buildtext():
             if btext[0] is not None: