with: use context manager in amend

with: use context manager for transaction in changegroup apply (This needs some line wrapping due to the additional indent level. -mpm)

with: use context manager for transaction in rebase

with: use context manager for transaction in qimport

with: use context manager for transaction in qfinish

with: use context manager for transaction in mercurial_sink

transaction: turn a transaction into a Python context manager This lets us greatly simply acquire/release cycles. If the block completes without raising an exception, the transaction is closed. Code pattern before: try: tr = repo.transaction('x') # zillions of lines of code tr.close() finally: tr.release() And after: with tr.transaction('x'): # ...