stack: show unstable state for the current revision if it is one (issue5553) Before this patch if the current revision is unstable, hg stack does not show the unstable state. This patch fixes that by showing both current and unstable state for the current revision if that's unstable.

topics: some minute fixes to the documentation which shows up in help I am not a native but these changes are simple and obvious.

topics: make sure we commit on new parents while changing topics (issue5441) While changing topics of a set of linear commits, we used to commit our new changesets with new topic on parents of its predecessor i.e. changeset before the topic change. If the topic of parent was also changed, that parent will become obsolete and hence resulting the cnew commit in unstable state. For a set of linear commits this repeats and we end up in a tree state as mentioned in the bug. This patch fixes the bug by checking whether the parent was obsoleted and if yes, commit on the new parent.

tests: add a test to show issue5441 in test-topic.t The issue will be fixed in the next patch and the test will be helpful to show that.

merge back with stable (test change from stable has been reverted)

Added tag 6.4.0 for changeset e60248f26f92

packaging: prepare version 6.4.0

readme: fix readme for future 6.4.0

test-compat: merge with mercurial-3.9

test-compat: merge with mercurial-4.0