Fix a bug where interrupting git-annex while it is updating the git-annex
branch could lead to git fsck complaining about missing tree objects.
Interrupting git-annex while regraftexports is running in a transition
that is forgetting git-annex branch history would leave the
repository with a git-annex branch that did not contain the tree shas
listed in export.log. That lets those trees be garbage collected.
A subsequent run of the same transition then regrafts the trees listed
in export.log into the git-annex branch. But those trees have been lost.
Note that both sides of `if neednewlocalbranch` are atomic now. I had
thought only the True side needed to be, but I do think there may be
cases where the False side needs to be as well.
Sponsored-by: Dartmouth College's OpenNeuro project
When building an adjusted unlocked branch, make pointer files executable
when the annex object file is executable.
This slows down git-annex adjust --unlock/--unlock-present by needing to
stat all annex object files in the tree. Probably not a significant
slowdown compared to other work they do, but I have not benchmarked.
I chose to leave git-annex adjust --unlock marked as stable, even though
get or drop of an object file can change whether it would make the pointer
file executable. Partly because making it unstable would slow down
re-adjustment, and partly for symmetry with the handling of an unlocked
pointer file that is executable when the content is dropped, which does not
remove its execute bit.
