commit c3c7af31dd1ac74d4d672bf5ff8c1dff07b4690a
Author: James Antill <james@and.org>
Date:   Tue May 31 16:02:09 2011 -0400

    Fail reverts of repomd.xml when we aren't doing timestamp checks. BZ 665919.

diff --git a/yum/yumRepo.py b/yum/yumRepo.py
index 6ba058c..cfc6581 100644
--- a/yum/yumRepo.py
+++ b/yum/yumRepo.py
@@ -1067,6 +1067,14 @@ class YumRepository(Repository, config.RepoConf):
 
     def _revertOldRepoXML(self):
         """ If we have older data available, revert to it. """
+
+        #  If we can't do a timestamp check, then we can be looking at a
+        # completely different repo. from last time ... ergo. we can't revert.
+        #  We still want the old data, so we don't download twice. So we
+        # pretend everything is good until the revert.
+        if self.timestamp_check:
+            raise Errors.RepoError, "Can't download or revert repomd.xml"
+
         if 'old_repo_XML' not in self._oldRepoMDData:
             self._oldRepoMDData = {}
             return
commit 48bbbb72793fac371c31c19f55e689e472031d90
Author: James Antill <james@and.org>
Date:   Tue May 31 17:31:24 2011 -0400

    Do the timestamp check the correct way around.

diff --git a/yum/yumRepo.py b/yum/yumRepo.py
index cfc6581..1568c54 100644
--- a/yum/yumRepo.py
+++ b/yum/yumRepo.py
@@ -1072,7 +1072,7 @@ class YumRepository(Repository, config.RepoConf):
         # completely different repo. from last time ... ergo. we can't revert.
         #  We still want the old data, so we don't download twice. So we
         # pretend everything is good until the revert.
-        if self.timestamp_check:
+        if not self.timestamp_check:
             raise Errors.RepoError, "Can't download or revert repomd.xml"
 
         if 'old_repo_XML' not in self._oldRepoMDData: