changeset 27928:c0f11347b107 stable

changegroup: don't support versions 01 and 02 with treemanifests Since it would be terribly expensive to convert between flat manifests and treemanifests, we have decided to simply not support changegroup version 01 and 02 with treemanifests. Therefore, let's stop announcing that we support these versions on treemanifest repos. Note that this means that older clients that try to clone from a treemanifest repo will fail. What happens is that the server, after this patch, finds that there are no common versions and raises "ValueError: no common changegroup version". This results in "abort: HTTP Error 500: Internal Server Error" on the client. Before this patch, it was no better: The server would instead find that there were directory manifest nodes to put in the changegroup 01 or 02 and raise an AssertionError on changegroup.py#668 (assert not tmfnodes), which would also appear as a 500 to the client.
author Martin von Zweigbergk <martinvonz@google.com>
date Tue, 19 Jan 2016 14:27:18 -0800
parents 0de4dfc9af0c
children 3b2ac2115464
files mercurial/changegroup.py
diffstat 1 files changed, 12 insertions(+), 6 deletions(-) [+]
line wrap: on
line diff
--- a/mercurial/changegroup.py	Tue Jan 19 08:22:27 2016 -0800
+++ b/mercurial/changegroup.py	Tue Jan 19 14:27:18 2016 -0800
@@ -947,12 +947,18 @@
 }
 
 def supportedversions(repo):
-    versions = _packermap.keys()
-    cg3 = ('treemanifest' in repo.requirements or
-           repo.ui.configbool('experimental', 'changegroup3') or
-           repo.ui.configbool('experimental', 'treemanifest'))
-    if not cg3:
-        versions.remove('03')
+    versions = set(_packermap.keys())
+    if ('treemanifest' in repo.requirements or
+        repo.ui.configbool('experimental', 'treemanifest')):
+        # Versions 01 and 02 support only flat manifests and it's just too
+        # expensive to convert between the flat manifest and tree manifest on
+        # the fly. Since tree manifests are hashed differently, all of history
+        # would have to be converted. Instead, we simply don't even pretend to
+        # support versions 01 and 02.
+        versions.discard('01')
+        versions.discard('02')
+    elif not repo.ui.configbool('experimental', 'changegroup3'):
+        versions.discard('03')
     return versions
 
 def getbundler(version, repo, bundlecaps=None):