update: resurrect bare update from null parent to tip-most branch head The situation is tricky if repository has no "default" branch, because "null" revision belongs to non-existent "default" branch. Before e1dd0de26557, bare update from null would bring us to the tip-most non-closed branch head. e1dd0de26557 removed the special handling of missing "default" branch since we wanted to stick to the uncommitted branch in that case. But, if the parent is "null" revision, and if the missing branch is "default", it shouldn't be an uncommitted branch. In this case, bare update should bring us to the tip-most head as before. This should fix the test breakage introduced by e1dd0de26557.

tests: run import-checker with tests .t files

import-checker: parse python code from .t files

import-checker: track filenames for SyntaxErrors

import-checker: track SyntaxErrors We don't really need to report SyntaxErrors, since in theory docchecker or a test will catch them, but they happen, and we can't just have the code crash, so for now, we're reporting them.

import-checker: refactor source reading This will allow .t files to generate multiple sources. It will also allow .py doctests to generate additional sources.

tests: make test-pathencode use print_function

tests: make test-run-tests use absolute_import

tests: make test-symlink-os-yes-fs-no use absolute_import

tests: make test-ui-color use absolute_import

tests: make test-url use absolute_import

tests: make test-trusted use absolute_import