On Thu, Nov 17 2022, Jeff King wrote:
> On Thu, Nov 17, 2022 at 05:31:13PM +0000, Glen Choo via GitGitGadget wrote:
> [...]
>> @@ -596,7 +603,7 @@ static void link_alt_odb_entries(struct repository *r, const char *alt,
>> return;
>> }
>>
>> - strbuf_add_absolute_path(&objdirbuf, r->objects->odb->path);
>> + strbuf_realpath(&objdirbuf, r->objects->odb->path, 1);
>> if (strbuf_normalize_path(&objdirbuf) < 0)
>> die(_("unable to normalize object directory: %s"),
>> objdirbuf.buf);
>
> Similarly here, I think we'd want to _replace_ the normalize with a
> realpath. There's no point in doing both. It's OK to die in this one
> because we assume the object directory can be normalized/realpath'd.
>
> So I'd have expected the code portion of your patch to be more like:
>
> diff --git a/object-file.c b/object-file.c
> index 957790098f..c6a195c6dd 100644
> --- a/object-file.c
> +++ b/object-file.c
> @@ -508,6 +508,7 @@ static int link_alt_odb_entry(struct repository *r, const struct strbuf *entry,
> {
> struct object_directory *ent;
> struct strbuf pathbuf = STRBUF_INIT;
> + struct strbuf tmp = STRBUF_INIT;
> khiter_t pos;
>
> if (!is_absolute_path(entry->buf) && relative_base) {
> @@ -516,12 +517,18 @@ static int link_alt_odb_entry(struct repository *r, const struct strbuf *entry,
> }
> strbuf_addbuf(&pathbuf, entry);
>
> - if (strbuf_normalize_path(&pathbuf) < 0 && relative_base) {
> - error(_("unable to normalize alternate object path: %s"),
> - pathbuf.buf);
> - strbuf_release(&pathbuf);
> - return -1;
> + if (!strbuf_realpath(&tmp, pathbuf.buf, 0)) {
> + if (relative_base) {
> + error(_("unable to normalize alternate object path: %s"),
> + pathbuf.buf);
> + strbuf_release(&pathbuf);
> + return -1;
> + }
> + /* allow broken paths from env per 37a95862c625 */
> + strbuf_addstr(&tmp, pathbuf.buf);
> }
> + strbuf_swap(&pathbuf, &tmp);
> + strbuf_release(&tmp);
>
> /*
> * The trailing slash after the directory name is given by
> @@ -596,10 +603,7 @@ static void link_alt_odb_entries(struct repository *r, const char *alt,
> return;
> }
>
> - strbuf_add_absolute_path(&objdirbuf, r->objects->odb->path);
> - if (strbuf_normalize_path(&objdirbuf) < 0)
> - die(_("unable to normalize object directory: %s"),
> - objdirbuf.buf);
> + strbuf_realpath(&objdirbuf, r->objects->odb->path, 1);
>
> while (*alt) {
> alt = parse_alt_odb_entry(alt, sep, &entry);
>
> The "tmp" swapping in link_alt_odb_entry is kind of unfortunate. It
> would be nice if there were an in-place version of strbuf_realpath, even
> if it was using two buffers under the hood (which is how the normalize
> code does it). And then the patch really would be s/normalize/realpath/,
> which is easier to understand.
>
> Possibly this should also be using the "forgiving" version. We
> eventually error out on missing entries later on, so it's not a big deal
> to error here. But it would let us keep the error message the same. I
> don't know that it matters much in practice.
This probably isn't worth it, but I wondered if this wouldn't be easier
if we pulled that memory management into the caller, it's not
performance sensitive (or maybe, how many alternatives do people have
:)), but an advantage of this is that we avoid the free()/malloc() if we
only get partway through, i.e. return early and keep looping.
In terms of general code smell & how we manage the "return" here, as
adding "RESULT_MUST_BE_USED" to this shows we never use the "0" or "-1"
(or any other...) return value.
That's been the case since this was added in c2f493a4ae1 (Transitively
read alternatives, 2006-05-07), so we can probably just make this a
"void" and ditch the returns if we're finding ourselves juggling these
return values...
object-file.c | 44 ++++++++++++++++++++++----------------------
1 file changed, 22 insertions(+), 22 deletions(-)
diff --git a/object-file.c b/object-file.c
index c6a195c6dd2..1a94d98e0c7 100644
--- a/object-file.c
+++ b/object-file.c
@@ -504,47 +504,43 @@ static void read_info_alternates(struct repository *r,
const char *relative_base,
int depth);
static int link_alt_odb_entry(struct repository *r, const struct strbuf *entry,
- const char *relative_base, int depth, const char *normalized_objdir)
+ const char *relative_base, int depth,
+ const char *normalized_objdir,
+ struct strbuf *pathbuf)
{
struct object_directory *ent;
- struct strbuf pathbuf = STRBUF_INIT;
struct strbuf tmp = STRBUF_INIT;
khiter_t pos;
if (!is_absolute_path(entry->buf) && relative_base) {
- strbuf_realpath(&pathbuf, relative_base, 1);
- strbuf_addch(&pathbuf, '/');
+ strbuf_realpath(pathbuf, relative_base, 1);
+ strbuf_addch(pathbuf, '/');
}
- strbuf_addbuf(&pathbuf, entry);
+ strbuf_addbuf(pathbuf, entry);
- if (!strbuf_realpath(&tmp, pathbuf.buf, 0)) {
- if (relative_base) {
- error(_("unable to normalize alternate object path: %s"),
- pathbuf.buf);
- strbuf_release(&pathbuf);
- return -1;
- }
+ if (!strbuf_realpath(&tmp, pathbuf->buf, 0)) {
+ if (relative_base)
+ return error(_("unable to normalize alternate object path: %s"),
+ pathbuf->buf);
/* allow broken paths from env per 37a95862c625 */
- strbuf_addstr(&tmp, pathbuf.buf);
+ strbuf_addstr(&tmp, pathbuf->buf);
}
- strbuf_swap(&pathbuf, &tmp);
+ strbuf_swap(pathbuf, &tmp);
strbuf_release(&tmp);
/*
* The trailing slash after the directory name is given by
* this function at the end. Remove duplicates.
*/
- while (pathbuf.len && pathbuf.buf[pathbuf.len - 1] == '/')
- strbuf_setlen(&pathbuf, pathbuf.len - 1);
+ while (pathbuf->len && pathbuf->buf[pathbuf->len - 1] == '/')
+ strbuf_setlen(pathbuf, pathbuf->len - 1);
- if (!alt_odb_usable(r->objects, &pathbuf, normalized_objdir, &pos)) {
- strbuf_release(&pathbuf);
+ if (!alt_odb_usable(r->objects, pathbuf, normalized_objdir, &pos))
return -1;
- }
CALLOC_ARRAY(ent, 1);
- /* pathbuf.buf is already in r->objects->odb_by_path */
- ent->path = strbuf_detach(&pathbuf, NULL);
+ /* pathbuf->buf is already in r->objects->odb_by_path */
+ ent->path = strbuf_detach(pathbuf, NULL);
/* add the alternate entry */
*r->objects->odb_tail = ent;
@@ -593,6 +589,7 @@ static void link_alt_odb_entries(struct repository *r, const char *alt,
{
struct strbuf objdirbuf = STRBUF_INIT;
struct strbuf entry = STRBUF_INIT;
+ struct strbuf pathbuf = STRBUF_INIT;
if (!alt || !*alt)
return;
@@ -610,8 +607,11 @@ static void link_alt_odb_entries(struct repository *r, const char *alt,
if (!entry.len)
continue;
link_alt_odb_entry(r, &entry,
- relative_base, depth, objdirbuf.buf);
+ relative_base, depth, objdirbuf.buf,
+ &pathbuf);
+ strbuf_reset(&pathbuf);
}
+ strbuf_release(&pathbuf);
strbuf_release(&entry);
strbuf_release(&objdirbuf);
}
