The "-l" option in "git branch -l" is an unfortunate short-hand for
"--create-reflog", but many users, both old and new, somehow expect
it to be something else, perhaps "--list". This step warns when "-l"
is used as a short-hand for "--create-reflog" and warns about the
future repurposing of the it when it is used.
* jk/branch-l-0-deprecation:
branch: deprecate "-l" option
t: switch "branch -l" to "branch --create-reflog"
t3200: unset core.logallrefupdates when testing reflog creation