Re: [PATCH] Remove a dead assignment

On Wed, May 25, 2011 at 12:23:44PM -0700, Junio C Hamano wrote:

Junio C Hamano [off-list ref] writes:

quoted

The if statement says "we might be passing NULL in fmt and in that case
please fall back to user_format" to human readers, but the compiler is too
stupid to infer such an intention, so you have to help it with your brain.
I have to wonder if the strbuf_expand() should be passing fmt instead of
user_format.  "git blame -L1082,+7 pretty.c" points at 5b16360 (pretty:
Initialize notes if %N is used, 2010-04-13).

The only callsite that is introduced by that patch passes NULL to fmt, so
a better fix might be to do something like this instead.

If somebody cares about the reusability of the code for other callsites
added in the future, we could do this instead.

I think this is what Johannes wanted to do from the beginning, and is a
better fix than my previous one to remove the fmt parameter altogether.

Actually, I am to blame for this interface, see:

  http://article.gmane.org/gmane.comp.version-control.git/144650

and my response:

  http://article.gmane.org/gmane.comp.version-control.git/144715

The resulting patch definitely has a bug (albeit one that could not be
triggered by current users), and should have had this:

-	strbuf_expand(&dummy, user_format, userformat_want_item, w);
+	strbuf_expand(&dummy, fmt, userformat_want_item, w);

all along.

I'm also OK with just tightening the interface to always use
user_format, as no callers who wanted the extra parameter have come up
in the past year.

Subject: userformat_find_requirements(): find requirement for the correct format

This function was introduced in 5b16360 (pretty: Initialize notes if %N is
used, 2010-04-13) to check what kind of information the "log --format=..."
user format string wants. The function can be passed a NULL instead of a
format string to ask it to check user_format variable kept by an earlier
call to save_user_format().

But it unconditionally checked user_format and not the string it was
given.  The only caller introduced by the change passes NULL, which
kept the bug unnoticed, until a new GCC noticed that there is an
assignment to fmt that is never used.

Acked-by: Jeff King <redacted>

Noticed-by: Chris Wilson's compiler

Heh.

-Peff