ui: add a parameter to set the temporary directory for edit
Until callsites are updated, this will have no effect. Once callsites
are updated, specifying experimental.editortmpinhg will create editor
temporary files in a subdirectory of .hg, which will make it easier
for tool integrations to determine what repository is in play when
they're asked to edit an hg-related file.
help: update help for `hg update` which was misleading (
issue5427)
templater: add '{envvars}' to access environment variables
Since the option for ui.exportableenviron is experimental, so is this template
until the underlying API is sorted out.
ui: introduce an experimental dict of exportable environment variables
Care needs to be taken to prevent leaking potentially sensitive environment
variables through hgweb, if template support for environment variables is to be
introduced. There are a few ideas about the API for preventing accidental
leaking [1]. Option 3 seems best from the POV of not needing to configure
anything in the normal case. I couldn't figure out how to do that, so guard it
with an experimental option for now.
[1] https://www.mercurial-scm.org/pipermail/mercurial-devel/2017-January/092383.html
tests: test experimental.spacemovesdown config for commit -i
The feature is still very experimental, but at least its behavior is captured
in the test.