[PATCH] bundle: avoid crash when when no good changegroup version found

[Martin von Zweigbergk]

# HG changeset patch
# User Martin von Zweigbergk <martinvonz at google.com>
# Date 1458972332 25200
#      Fri Mar 25 23:05:32 2016 -0700
# Node ID 36d7ddd387bf91b2623ee2a020279ef5c7af7669
# Parent  5474dc73680f96e79ae3c255fb01b7943b2fc2d1
bundle: avoid crash when when no good changegroup version found

When using treemanifests, only changegroup3 bundles can be
created. However, there is currently no way of requesting a
changegroup3 bundle, so we run into an assertion in
changegroup.getbundler() when trying to get a changroup2
bundler. Let's avoid the traceback and print a short error message
instead.

diff -r 5474dc73680f -r 36d7ddd387bf mercurial/commands.py
--- a/mercurial/commands.py	Mon Mar 28 09:12:03 2016 +0200
+++ b/mercurial/commands.py	Fri Mar 25 23:05:32 2016 -0700
@@ -1399,6 +1399,10 @@
         base = scmutil.revrange(repo, opts.get('base'))
     # TODO: get desired bundlecaps from command line.
     bundlecaps = None
+    if cgversion not in changegroup.supportedoutgoingversions(repo):
+        raise error.Abort(_("repository does not support bundle version %s") %
+                          cgversion)
+
     if base:
         if dest:
             raise error.Abort(_("--base is incompatible with specifying "
diff -r 5474dc73680f -r 36d7ddd387bf tests/test-treemanifest.t
--- a/tests/test-treemanifest.t	Mon Mar 28 09:12:03 2016 +0200
+++ b/tests/test-treemanifest.t	Fri Mar 25 23:05:32 2016 -0700
@@ -736,3 +736,9 @@
   bundle requirements: generaldelta, revlogv1, treemanifest
   $ hg debugbundle --spec repo-packed.hg
   none-packed1;requirements%3Dgeneraldelta%2Crevlogv1%2Ctreemanifest
+
+Bundle with changegroup2 is not supported
+
+  $ hg -R deeprepo bundle --all -t v2 deeprepo.bundle
+  abort: repository does not support bundle version 02
+  [255]