Junio C Hamano <gitster@xxxxxxxxx> writes:
> Just as the prefix-less variant was idempotent and that was the
> reason why cmd_diff_files() had its own precompose() even if the
> incoming argv[] is supposed to be already precomposed because it
> was processed in another call to precompose() in run_builtin(),
> this patch keeps these seemingly redundant calls, because it is not
> meant as a clean-up but as a bugfix for the prefix part.
>
> OK. ... Ah, no, the call in run_builtin() is a new thing. We didn't
> have it, and the redundant call is what this patch introduced, so
> we need to be a bit more careful about the analysis here. It is one
> thing to say "we leave the existing iffy code and address only a
> single bug" and do so. It is entirely different to say so and then
> do "we introduce an iffy code and address only a single bug". We
> need to admit that what we added _is_ iffy but supposed to be safe.
> Just saying "it is supposed to be safe" without saying why it is
> iffy is dishonest and does not help future developers who may want
> to jump in and clean the code.
>
> Perhaps
>
> Now add it into git.c::run_builtin() as well. Existing
> precompose calls in diff-files.c and others would become
> redundant but because we do not want to make sure that there
> is no way for the control to reach them without passing
> run_builtin(), we'll keep them in place just in case. The
> calls to precompose() are idempotent so it should not hurt.
>
> or something?
FYI, I've tweaked the proposed log message like the following before
queuing. I think that would be explicit enough to remind us that we
may be able to improve the situation fairly easily.
Thanks.
1: 071dfe8793 ! 1: 5c327502db MacOS: precompose_argv_prefix()
@@ Commit message
The original patch for preocomposed unicode, 76759c7dff53, placed
precompose_argv() into parse-options.c
- Now add it into git.c (as well) for commands that don't use parse-options.
- Note that precompose() may be called twice - it is idempotent.
+
+ Now add it into git.c::run_builtin() as well. Existing precompose
+ calls in diff-files.c and others may become redundant, and if we
+ audit the callflows that reach these places to make sure that they
+ can never be reached without going through the new call added to
+ run_builtin(), we might be able to remove these existing ones.
+
+ But in this commit, we do not bother to do so and leave these
+ precompose callsites as they are. Because precompose() is
+ idempotent and can be called on an already precomposed string
+ safely, this is safer than removing existing calls without fully
+ vetting the callflows.
There is certainly room for cleanups - this change intends to be a bug fix.
Cleanups needs more tests in e.g. t/t3910-mac-os-precompose.sh, and should
