Am 07.10.2016 um 02:46 schrieb Jeff King:
On Tue, Sep 27, 2016 at 09:11:58PM +0200, René Scharfe wrote:
Call strbuf_add_unique_abbrev() to add abbreviated hashes to strbufs
instead of taking detours through find_unique_abbrev() and its static
buffer. This is shorter and a bit more efficient.
[...]
diff --git a/diff.c b/diff.c
index a178ed3..be11e4e 100644
--- a/diff.c
+++ b/diff.c
@@ -3109,7 +3109,7 @@ static void fill_metainfo(struct strbuf *msg,
}
strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
find_unique_abbrev(one->oid.hash, abbrev));
- strbuf_addstr(msg, find_unique_abbrev(two->oid.hash, abbrev));
+ strbuf_add_unique_abbrev(msg, two->oid.hash, abbrev);
if (one->mode == two->mode)
strbuf_addf(msg, " %06o", one->mode);
strbuf_addf(msg, "%s\n", reset);
This one is an interesting case, and maybe a good example of why blind
coccinelle usage can have some pitfalls. :)
Thank you for paying attention. :) In general I agree that the
surrounding code of such changes should be checked; the issue at hand
could be part of a bigger problem.
We get rid of the strbuf_addstr(), but notice that we leave untouched
the find_unique_abbrev() call immediately above. There was a symmetry to
the two that has been lost.
Probably either:
strbuf_addf(msg, "%s%sindex %s..%s", line_prefix, set
find_unique_abbrev(one->oid.hash, abbrev),
find_unique_abbrev(two->oid.hash, abbrev));
or:
strbuf_addf(msg, "%s%sindex ", line_prefix, set);
strbuf_add_unique_abbrev(msg, one->oid.hash, abbrev);
strbuf_addstr(msg, "..");
strbuf_add_unique_abbrev(msg, two->oid.hash, abbrev);
would be a more appropriate refactoring. The problem is in the original
patch (which also lacks symmetry; either this predates the multi-buffer
find_unique_abbrev, or the original author didn't know about it), but I
think your refactor makes it slightly worse.
I still think the automatically generated patch is a net win, but we
shouldn't stop there.
I noticed because I have another series which touches these lines, and
it wants to symmetrically swap out find_unique_abbrev for something
else. :) I don't think it's a big enough deal to switch now (and I've
already rebased my series which will touch these lines), but I wanted to
mention it as a thing to watch out for as we do more of these kinds of
automated transformations.
OK, then I'll wait for that series to land.
--- a/submodule.c
+++ b/submodule.c
@@ -396,7 +396,7 @@ static void show_submodule_header(FILE *f, const char *path,
find_unique_abbrev(one->hash, DEFAULT_ABBREV));
if (!fast_backward && !fast_forward)
strbuf_addch(&sb, '.');
- strbuf_addstr(&sb, find_unique_abbrev(two->hash, DEFAULT_ABBREV));
+ strbuf_add_unique_abbrev(&sb->hash, two, DEFAULT_ABBREV);
This one is a similar situation, I think.
Yes, and there are some more. Will take a look.
I don't know how to crack printf-style formats using semantic patches.
It's easy for fixed formats (silly example):
- strbuf_addf(sb, "%s%s", a, b);
+ strbuf_addf(sb, "%s", a);
+ strbuf_addf(sb, "%s", b);
But how to do that for arbitrary formats? Probably not worth it..
René