bundle: fix bundle generation for empty changegroup

mercurial/commands.py

@@ -564,6 +564,10 b' def bundle(ui, repo, fname, dest=None, *'
         revs, checkout = hg.addbranchrevs(repo, other, branches, revs)
         o = repo.findoutgoing(other, force=opts.get('force'))
 
+    if not o:
+        ui.status(_("no changes found\n"))
+        return
+
     if revs:
         cg = repo.changegroupsubset(o, revs, 'bundle')
     else:

tests/test-bundle-r

@@ -72,6 +72,8 b' hg -R test bundle --base 2 -r tip test-b'
 hg -R test bundle --base 2 -r 7 test-bundle-branch2.hg
 hg -R test bundle --base 2 test-bundle-all.hg
 hg -R test bundle --base 3 -r tip test-bundle-should-fail.hg
+# empty bundle
+hg -R test bundle --base 7 --base 8 test-bundle-empty.hg
 
 # issue76 msg2163
 hg -R test bundle --base 3 -r 3 -r 3 test-bundle-cset-3.hg

tests/test-bundle-r.out

@@ -162,6 +162,7 b' 2 changesets found'
 4 changesets found
 6 changesets found
 1 changesets found
+no changes found
 1 changesets found
 4 changesets found
 updating to branch default