hg-core: add format-bytes dependency This will be used in the next patch to make error messages that require bytestring concatenation clearer. Differential Revision: https://phab.mercurial-scm.org/D9409

rebase: handle the case when nothing to rebase (dry-run) In dry-run mode, even when there was no rebase in progress it tried to abort (for context, at the end of dry-run mode we abort the in-memory performed rebase) because we were not early checking if there was any rebase started. Changes in test file reflect the fixed behavior. Differential Revision: https://phab.mercurial-scm.org/D9659

rebase: add test to demonstrate an issue in dry-run In dry-run mode, the case when there is nothing to rebase is not handled correctly. Added test show that it try to abort a rebase while there is no rebase in progress. This will be fixed in next patch. Differential Revision: https://phab.mercurial-scm.org/D9658

pycompat: fix typos Differential Revision: https://phab.mercurial-scm.org/D9662

chg: format code by clang-format version 11.0.1-+rc1-1 test-check-clang-format.t started failing on my Debian sid environment, and new style looks slightly better. So let's bump the required clang-format version to 11.

test-check-interface: do not expect bare "python" executable exists The test would crash if python executable had version suffix.

procutil: assign pseudo file object if sys.stdout/stderr is missing This basically simulates the Python 2 behavior. If libc stdio were used, these file objects would be available and raise EBADF. There is subtle difference between py2 and py3, but I think py3 behavior (i.e. exit 255) is more correct. "if" conditions are adjust so that they look similar to dispatch.initstdio().

procutil: introduce pseudo file object that just raises EBADF This should be safer than closing underlying fd as the fd may be reused. On Python 2, closed sys.stdin could be redirected to a random file having fd=0, but we'd be better not copying this behavior. Only readinto() and write() are implemented according to the following ABC table. fileno() is not implemented since fd=0/1/2 may be assigned later to other files. https://docs.python.org/3/library/io.html#class-hierarchy

dispatch: gate against missing stdout/stderr We do need procutil.stdin/stdout/stderr, but we don't care much for sys.std*. Let's leave them be None as it is the Python 3 way.

dispatch: remove stale comment about fdopen()-ed stdio On Python 3, stdout is just wrapped by LineBufferedWrapper.