On Wed, Aug 01 2018, Junio C Hamano wrote:
> The option help text for the force-with-lease option to "git push"
> reads like this:
>
> $ git push -h 2>&1 | grep -e force-with-lease
> --force-with-lease[=<refname>:<expect>]
>
> which come from this
>
> 0, CAS_OPT_NAME, &cas, N_("refname>:<expect"),
>
> in the source code, with an aparent lack of "<" and ">" at both
> ends.
>
> It turns out that parse-options machinery takes the whole string and
> encloses it inside a pair of "<>", expecting that it is a single
> placeholder. The help string was written in a funnily unbalanced
> way knowing that the end result would balance out.
>
> Add a comment to save future readers from wasting time just like I
> did ;-)
There's something worth fixing here for sure...
> + /* N_() will get "<>" around, resulting in
> "<refname>:<expect>" */
...but this comment isn't accurate at all, N_() doesn't wrap the string
with <>'s, as can be seen by applying this patch:
- 0, CAS_OPT_NAME, &cas, N_("refname>:<expect"),
+ 0, CAS_OPT_NAME, &cas, "refname>:<expect",
Resulting in the same output:
$ ./git --exec-path=$PWD push -h 2>&1 | grep -e force-with-lease
--force-with-lease[=<refname>:<expect>]
Rather, it's the usage_argh() function in parse-options.c that's doing
this. Looks like the logic was added in 29f25d493c ("parse-options: add
PARSE_OPT_LITERAL_ARGHELP for complicated argh's", 2009-05-21).
Also because of this I looked at:
$ git grep -P 'N_\("<'
Which shows e.g.:
builtin/difftool.c:706: OPT_STRING('t', "tool", &difftool_cmd,
N_("<tool>"),
builtin/difftool.c:714: OPT_STRING('x', "extcmd", &extcmd,
N_("<command>"),
Producing this bug:
$ git difftool -h 2>&1|grep '<<'
-t, --tool <<tool>> use the specified diff tool
-x, --extcmd <<command>>
But these all do the right thing for some reason, just looked briefly
and didn't see how they're different & manage to avoid this:
builtin/read-tree.c:134: { OPTION_STRING, 0, "prefix",
&opts.prefix, N_("<subdirectory>/"),
builtin/show-branch.c:673: { OPTION_CALLBACK, 'g', "reflog",
&reflog_base, N_("<n>[,<base>]"),
builtin/update-index.c:969:
N_("<mode>,<object>,<path>"),
builtin/write-tree.c:27: { OPTION_STRING, 0, "prefix",
&prefix, N_("<prefix>/"),
