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Re: [PATCH v2 3/4] builtin/stash: provide a way to export stashes to a ref

From
brian m. carlson <sandals@crustytoothpaste.net>
Date
Apr 5, 2022, 10:55 UTC
Message-ID
<YkwgGjj0JIcOhlMH@camp.crustytoothpaste.net>
In-Reply-To
<220331.86pmm2swm9.gmgdl@evledraar.gmail.com>
On 2022-03-31 at 01:56:01, Ævar Arnfjörð Bjarmason wrote:
Show 23 quoted lines
> 
> On Tue, Mar 29 2022, brian m. carlson wrote:
> 
> > diff --git a/Documentation/git-stash.txt b/Documentation/git-stash.txt
> > index 6e15f47525..162110314e 100644
> > --- a/Documentation/git-stash.txt
> > +++ b/Documentation/git-stash.txt
> > @@ -20,6 +20,7 @@ SYNOPSIS
> >  'git stash' clear
> >  'git stash' create [<message>]
> >  'git stash' store [-m|--message <message>] [-q|--quiet] <commit>
> > +'git stash' export ( --print | --to-ref <ref> ) [<stash>...]
> >  
> >  DESCRIPTION
> >  -----------
> > @@ -151,6 +152,12 @@ store::
> >  	reflog.  This is intended to be useful for scripts.  It is
> >  	probably not the command you want to use; see "push" above.
> >  
> > +export ( --print | --to-ref <ref> ) [<stash>...]::
> > +
> 
> I think this extra \n here isn't needed.

All the rest of the entries have it that way. Junio likes it, you don't, but it's consistent with the rest of the file and I'm just following along.

Show 8 quoted lines
> > +static const char * const git_stash_export_usage[] = {
> > +	N_("git stash export (--print | --to-ref <ref>) [<stash>...]"),
> > +	NULL
> > +};
> > +
> > +
> 
> Stray too-much-whitespace.
Fixed in v3 already.
Show 11 quoted lines
> > +	this = lookup_commit_reference(the_repository, oid);
> > +	buffer = get_commit_buffer(this, &bufsize);
> > +	orig_author = find_commit_header(buffer, "author", &author_len);
> > +	orig_committer = find_commit_header(buffer, "committer", &committer_len);
> > +	p = memmem(buffer, bufsize, "\n\n", 2);
> > +
> > +	if (!orig_author || !orig_committer || !p) {
> > +		error(_("cannot parse commit %s"), oid_to_hex(oid));
> > +		goto out;
> 
> ..isn't this a logic error, shouldn't we return -1 here?
Yes, it is.
> better as "ret = error(..."?
Yup.  v4 will have it fixed in both places.
> Can nalloc be moved into the if=else scopes?

It _can_, but it's used in both, so I don't see a particular reason to do so.

> Some very long lines here.
Will wrap in v4.
Show 11 quoted lines
> > +		return error(_("unable to write base commit"));
> > +
> > +	prev = lookup_commit_reference(the_repository, &base);
> > +
> > +	if (argc) {
> > +		/*
> > +		 * Find each specified stash, and load data into the array.
> > +		 */
> > +		for (int i = 0; i < argc; i++) {
> 
> ...as this is size_t, not int.
I'll make argc int.
Show 11 quoted lines
> > +				goto out;
> > +			}
> > +		}
> > +	} else {
> > +		/*
> > +		 * Walk the reflog, finding each stash entry, and load data into the
> > +		 * array.
> > +		 */
> > +		for (int i = 0;; i++) {
> 
> Aside from the C99 dependency Junio mentioned, this should also be size_t.

Nope. I specifically decided not to do that and mentioned it in the cover letter. Since Windows doesn't let us have nice things like %zu, I'm going to switch to int here and be consistent. I'm not coding for 16-bit systems here and I feel 2 billion stashes is sufficient for the needs of the project for the indefinite future based on the capabilities of current human beings.

The C99 dependency has been removed in v3.
Show 10 quoted lines
> > +	/*
> > +	 * Now, create a set of commits identical to the regular stash commits,
> > +	 * but where their first parents form a chain to our original empty
> > +	 * base commit.
> > +	 */
> > +	for (int i = nitems - 1; i >= 0; i--) {
> 
> Did you spot my "count down" suggestion in
> https://lore.kernel.org/git/220311.86bkydi65v.gmgdl@evledraar.gmail.com/
> on the v1?

I did, and I prefer this approach. That would be necessary if we were using size_t here, but we're not.

Show 21 quoted lines
> > +		struct commit_list *parents = NULL;
> > +		struct commit_list **next = &parents;
> > +		struct object_id out;
> > +
> > +		next = commit_list_append(prev, next);
> > +		next = commit_list_append(lookup_commit_reference(the_repository, &items[i]), next);
> > +		if (write_commit_with_parents(&out, &items[i], parents)) {
> 
> Here we returned -1 from this earlier, I think this would be more
> straightforward as:
> 	
> 	res = write_commit_with_parents(...)
> 	if (res < 0)
> 		goto out;
> 	
> 
> > +			res = -1;
> > +			goto out;
> 
> So one doesn't have to wonder why we're ignoring the error value, and
> using -1, but then treating all non-zero as errors.
That will be fixed in v4.
> It looks like we don't need to initialize this.
It'll be removed in v4.
Show 7 quoted lines
> > +	ret = do_export_stash(ref, argc, argv);
> > +	return ret;
> 
> Aside from the "ret" case above, maybe this would be better if the
> "action" check became a swith, then the compiler would help check it
> against the enum, and this wouldn't implicitly be both ACTION_PRINT and
> ACTION_TO_REF, but could be done via a fall-through.

Normally I'm a big fan of switch statements, but I don't feel in this case that it logically represents the current code. I think, given the context, that an if-else is easier to read.

-- 
brian m. carlson (he/him or they/them)
Toronto, Ontario, CA
Previous: Junio C HamanoNext: Ævar Arnfjörð Bjarmason
Message 38 of 76 in “Importing and exporting stashes to refs”
  1. 0/6 Importing and exporting stashes to refsbrian m. carlson, Mar 10, 2022
  2. 2/6 builtin/stash: fill in all commit databrian m. carlson, Mar 10, 2022
  3. Junio C HamanoMar 16, 2022
  4. 1/6 builtin/stash: factor out generic function to look up stash infobrian m. carlson, Mar 10, 2022
  5. 3/6 object-name: make get_oid quietly return an errorbrian m. carlson, Mar 10, 2022
  6. Junio C HamanoMar 16, 2022
  7. Drew StoleeMar 16, 2022
  8. brian m. carlsonMar 16, 2022
  9. 4/6 builtin/stash: provide a way to export stashes to a refbrian m. carlson, Mar 10, 2022
  10. Ævar Arnfjörð BjarmasonMar 11, 2022
  11. Phillip WoodMar 14, 2022
  12. Phillip WoodMar 15, 2022
  13. brian m. carlsonMar 16, 2022
  14. C99 %zu support (on MSVC) (was: [PATCH 4/6] builtin/stash: provide a way to export stashes to a ref)Ævar Arnfjörð Bjarmason, Mar 18, 2022
  15. Phillip WoodMar 18, 2022
  16. Johannes SchindelinMar 24, 2022
  17. ssize_t portability (was: [PATCH 4/6] builtin/stash: provide a way to export stashes to a ref)Ævar Arnfjörð Bjarmason, Mar 18, 2022
  18. Junio C HamanoMar 16, 2022
  19. 6/6 doc: add stash export and import to docsbrian m. carlson, Mar 10, 2022
  20. Junio C HamanoMar 16, 2022
  21. Junio C HamanoMar 16, 2022
  22. 5/6 builtin/stash: provide a way to import stashes from a refbrian m. carlson, Mar 10, 2022
  23. Junio C HamanoMar 16, 2022
  24. brian m. carlsonMar 16, 2022
  25. Junio C HamanoMar 10, 2022
  26. brian m. carlsonMar 10, 2022
  27. Junio C HamanoMar 10, 2022
  28. brian m. carlsonMar 10, 2022
  29. 0/4 Importing and exporting stashes to refsbrian m. carlson, Mar 29, 2022
  30. 2/4 builtin/stash: factor out revision parsing into a functionbrian m. carlson, Mar 29, 2022
  31. 1/4 object-name: make get_oid quietly return an errorbrian m. carlson, Mar 29, 2022
  32. 4/4 builtin/stash: provide a way to import stashes from a refbrian m. carlson, Mar 29, 2022
  33. 3/4 builtin/stash: provide a way to export stashes to a refbrian m. carlson, Mar 29, 2022
  34. Junio C HamanoMar 30, 2022
  35. brian m. carlsonMar 30, 2022
  36. Ævar Arnfjörð BjarmasonMar 31, 2022
  37. Junio C HamanoMar 31, 2022
  38. brian m. carlsonApr 5, 2022
  39. Ævar Arnfjörð BjarmasonApr 6, 2022
  40. Junio C HamanoApr 6, 2022
  41. Ævar Arnfjörð BjarmasonMar 31, 2022
  42. brian m. carlsonApr 5, 2022
  43. Junio C HamanoMar 31, 2022
  44. Ævar Arnfjörð BjarmasonMar 31, 2022
  45. 0/4 Importing and exporting stashes to refsbrian m. carlson, Apr 3, 2022
  46. 1/4 object-name: make get_oid quietly return an errorbrian m. carlson, Apr 3, 2022
  47. 2/4 builtin/stash: factor out revision parsing into a functionbrian m. carlson, Apr 3, 2022
  48. Phillip WoodApr 4, 2022
  49. 4/4 builtin/stash: provide a way to import stashes from a refbrian m. carlson, Apr 3, 2022
  50. Ævar Arnfjörð BjarmasonApr 4, 2022
  51. brian m. carlsonApr 5, 2022
  52. Ævar Arnfjörð BjarmasonApr 6, 2022
  53. 3/4 builtin/stash: provide a way to export stashes to a refbrian m. carlson, Apr 3, 2022
  54. Ævar Arnfjörð BjarmasonApr 4, 2022
  55. Junio C HamanoApr 4, 2022
  56. Junio C HamanoApr 4, 2022
  57. Ævar Arnfjörð BjarmasonApr 4, 2022
  58. brian m. carlsonApr 5, 2022
  59. 0/4 Importing and exporting stashes to refsbrian m. carlson, Apr 7, 2022
  60. 3/4 builtin/stash: provide a way to export stashes to a refbrian m. carlson, Apr 7, 2022
  61. Ævar Arnfjörð BjarmasonApr 13, 2022
  62. Ævar Arnfjörð BjarmasonApr 13, 2022
  63. Ævar Arnfjörð BjarmasonApr 13, 2022
  64. 2/4 builtin/stash: factor out revision parsing into a functionbrian m. carlson, Apr 7, 2022
  65. 1/4 object-name: make get_oid quietly return an errorbrian m. carlson, Apr 7, 2022
  66. 4/4 builtin/stash: provide a way to import stashes from a refbrian m. carlson, Apr 7, 2022
  67. Jonathan TanApr 12, 2022
  68. brian m. carlsonApr 13, 2022
  69. Jonathan TanApr 13, 2022
  70. Ævar Arnfjörð BjarmasonApr 13, 2022
  71. Jonathan TanApr 13, 2022
  72. Junio C HamanoApr 13, 2022
  73. brian m. carlsonApr 13, 2022
  74. Junio C HamanoApr 13, 2022
  75. Ævar Arnfjörð BjarmasonApr 13, 2022
  76. Ævar Arnfjörð BjarmasonApr 13, 2022

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