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From: Alban Gruin <alban.gruin@gmail.com>
To: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Cc: git@vger.kernel.org, Junio C Hamano <gitster@pobox.com>,
	Phillip Wood <phillip.wood123@gmail.com>,
	Derrick Stolee <stolee@gmail.com>
Subject: Re: [PATCH v7 08/15] merge-one-file: rewrite in C
Date: Tue, 23 Mar 2021 21:53:41 +0100	[thread overview]
Message-ID: <c968a6b8-bc0e-04f0-b72d-9fef05b60bd8@gmail.com> (raw)
In-Reply-To: <nycvar.QRO.7.76.6.2103222303210.50@tvgsbejvaqbjf.bet>

Hi Johannes,

Le 22/03/2021 à 23:20, Johannes Schindelin a écrit :
> Hi Alban,
> 
> On Wed, 17 Mar 2021, Alban Gruin wrote:
> 

>> @@ -69,10 +69,13 @@ int cmd_merge_index(int argc, const char **argv, const char *prefix)
>>
>>  	if (skip_prefix(pgm, "--use=", &use_internal)) {
>>  		if (!strcmp(use_internal, "merge-one-file"))
>> -			pgm = "git-merge-one-file";
>> +			merge_action = merge_one_file_func;
>>  		else
>>  			die(_("git merge-index: unknown internal program %s"), use_internal);
>> -	}
>> +
>> +		repo_hold_locked_index(r, &lock, LOCK_DIE_ON_ERROR);
>> +	} else
>> +		merge_action = merge_one_file_spawn;
> 
> I would have a slight preference to keep the default initializer, because
> that makes it easer to reason about. But if you _want_ to keep this patch
> as-is, I won't object.
> 

Yeah, not sure why I did this.  I'll change this.

> It is a bit sad that the conversion cannot be done more incrementally, as
> there is a lot to unpack in the many different cases that are handled. It
> looks correct, though.
> 
> Just one thing:
> 
>>
>>  	for (; i < argc; i++) {
>>  		const char *arg = argv[i];
>> diff --git a/builtin/merge-one-file.c b/builtin/merge-one-file.c
>> new file mode 100644
>> index 0000000000..ad99c6dbd4
>> --- /dev/null
>> +++ b/builtin/merge-one-file.c
>> @@ -0,0 +1,94 @@
>> +/*
>> + * Builtin "git merge-one-file"
>> + *
>> + * Copyright (c) 2020 Alban Gruin
>> + *
>> + * Based on git-merge-one-file.sh, written by Linus Torvalds.
>> + *
>> + * This is the git per-file merge utility, called with
>> + *
>> + *   argv[1] - original file object name (or empty)
>> + *   argv[2] - file in branch1 object name (or empty)
>> + *   argv[3] - file in branch2 object name (or empty)
>> + *   argv[4] - pathname in repository
>> + *   argv[5] - original file mode (or empty)
>> + *   argv[6] - file in branch1 mode (or empty)
>> + *   argv[7] - file in branch2 mode (or empty)
>> + *
>> + * Handle some trivial cases. The _really_ trivial cases have been
>> + * handled already by git read-tree, but that one doesn't do any merges
>> + * that might change the tree layout.
>> + */
>> +
>> +#include "cache.h"
>> +#include "builtin.h"
>> +#include "lockfile.h"
>> +#include "merge-strategies.h"
>> +
>> +static const char builtin_merge_one_file_usage[] =
>> +	"git merge-one-file <orig blob> <our blob> <their blob> <path> "
>> +	"<orig mode> <our mode> <their mode>\n\n"
>> +	"Blob ids and modes should be empty for missing files.";
>> +
>> +static int read_mode(const char *name, const char *arg, unsigned int *mode)
>> +{
>> +	char *last;
>> +	int ret = 0;
>> +
>> +	*mode = strtol(arg, &last, 8);
>> +
>> +	if (*last)
>> +		ret = error(_("invalid '%s' mode: expected nothing, got '%c'"), name, *last);
>> +	else if (!(S_ISREG(*mode) || S_ISDIR(*mode) || S_ISLNK(*mode)))
>> +		ret = error(_("invalid '%s' mode: %o"), name, *mode);
>> +
>> +	return ret;
>> +}
>> +
>> +int cmd_merge_one_file(int argc, const char **argv, const char *prefix)
>> +{
>> +	struct object_id orig_blob, our_blob, their_blob,
>> +		*p_orig_blob = NULL, *p_our_blob = NULL, *p_their_blob = NULL;
>> +	unsigned int orig_mode = 0, our_mode = 0, their_mode = 0, ret = 0;
>> +	struct lock_file lock = LOCK_INIT;
>> +	struct repository *r = the_repository;
>> +
>> +	if (argc != 8)
>> +		usage(builtin_merge_one_file_usage);
>> +
>> +	if (repo_read_index(r) < 0)
>> +		die("invalid index");
>> +
>> +	repo_hold_locked_index(r, &lock, LOCK_DIE_ON_ERROR);
>> +
>> +	if (!get_oid_hex(argv[1], &orig_blob)) {
>> +		p_orig_blob = &orig_blob;
>> +		ret = read_mode("orig", argv[5], &orig_mode);
>> +	} else if (!*argv[1] && *argv[5])
>> +		ret = error(_("no 'orig' object id given, but a mode was still given."));
> 
> Here, it looks as if the case of an empty `argv[1]` is not handled
> _explicitly_, but we rely on `get_oid_hex()` to return non-zero, and then
> we rely on the second arm _also_ not re-assigning `orig_blob`.
> 
> I wonder whether this could be checked, and whether it would make sense to
> fold this, along with most of these 5 lines, into the `read_mode()` helper
> function (DRYing up the code even further).
> 

Do you mean rewriting the first condition to read like this:

    if (*argv[1] && !get_oid_hex(argv[1], &orig_blob)) {

?

In which case yes, I can do that.

BTW the two lasts calls to read_mode() should be like

    err |= read_mode(…);

Cheers,
Alban

> As for the rest of the patch, it is totally possible that I missed a bug,
> but it looks correct to me, and the added regression tests give me a good
> feeling about the patch, too.
> 
> Thanks,
> Dscho
> 

  reply	other threads:[~2021-03-23 20:54 UTC|newest]

Thread overview: 173+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-25 12:19 [RFC PATCH v1 00/17] Rewrite the remaining merge strategies from shell to C Alban Gruin
2020-06-25 12:19 ` [RFC PATCH v1 01/17] t6027: modernise tests Alban Gruin
2020-06-25 12:19 ` [RFC PATCH v1 02/17] merge-one-file: rewrite in C Alban Gruin
2020-06-25 14:55   ` Chris Torek
2020-06-25 15:16   ` Phillip Wood
2020-06-25 18:17     ` Phillip Wood
2020-06-26 14:33       ` Phillip Wood
2020-07-12 11:22     ` Alban Gruin
2020-06-25 12:19 ` [RFC PATCH v1 03/17] merge-one-file: remove calls to external processes Alban Gruin
2020-06-25 12:19 ` [RFC PATCH v1 04/17] merge-one-file: use error() instead of fprintf(stderr, ...) Alban Gruin
2020-06-25 12:19 ` [RFC PATCH v1 05/17] merge-one-file: libify merge_one_file() Alban Gruin
2020-06-25 12:19 ` [RFC PATCH v1 06/17] merge-index: libify merge_one_path() and merge_all() Alban Gruin
2020-06-26 10:13   ` Phillip Wood
2020-06-26 14:32     ` Phillip Wood
2020-07-12 11:36     ` Alban Gruin
2020-07-12 18:02       ` Phillip Wood
2020-07-12 20:10         ` Alban Gruin
2020-06-25 12:19 ` [RFC PATCH v1 07/17] merge-resolve: rewrite in C Alban Gruin
2020-06-25 12:19 ` [RFC PATCH v1 08/17] merge-resolve: remove calls to external processes Alban Gruin
2020-06-25 12:19 ` [RFC PATCH v1 09/17] merge-resolve: libify merge_resolve() Alban Gruin
2020-06-25 12:19 ` [RFC PATCH v1 10/17] merge-recursive: move better_branch_name() to merge.c Alban Gruin
2020-06-25 12:19 ` [RFC PATCH v1 11/17] merge-octopus: rewrite in C Alban Gruin
2020-06-25 12:19 ` [RFC PATCH v1 12/17] merge-octopus: remove calls to external processes Alban Gruin
2020-06-25 12:19 ` [RFC PATCH v1 13/17] merge-octopus: libify merge_octopus() Alban Gruin
2020-06-25 12:19 ` [RFC PATCH v1 14/17] merge: use the "resolve" strategy without forking Alban Gruin
2020-06-25 12:19 ` [RFC PATCH v1 15/17] merge: use the "octopus" " Alban Gruin
2020-06-25 12:19 ` [RFC PATCH v1 16/17] sequencer: use the "resolve" " Alban Gruin
2020-06-25 16:11   ` Phillip Wood
2020-07-12 11:27     ` Alban Gruin
2020-06-25 12:19 ` [RFC PATCH v1 17/17] sequencer: use the "octopus" merge " Alban Gruin
2020-09-01 10:56 ` [PATCH v2 00/11] Rewrite the remaining merge strategies from shell to C Alban Gruin
2020-09-01 10:56   ` [PATCH v2 01/11] t6027: modernise tests Alban Gruin
2020-09-01 10:56   ` [PATCH v2 02/11] merge-one-file: rewrite in C Alban Gruin
2020-09-01 21:06     ` Junio C Hamano
2020-09-02 14:50       ` Alban Gruin
2020-09-01 10:56   ` [PATCH v2 03/11] merge-index: libify merge_one_path() and merge_all() Alban Gruin
2020-09-01 21:11     ` Junio C Hamano
2020-09-02 15:37       ` Alban Gruin
2020-09-01 10:56   ` [PATCH v2 04/11] merge-index: don't fork if the requested program is `git-merge-one-file' Alban Gruin
2020-09-01 10:56   ` [PATCH v2 05/11] merge-resolve: rewrite in C Alban Gruin
2020-09-01 10:57   ` [PATCH v2 06/11] merge-recursive: move better_branch_name() to merge.c Alban Gruin
2020-09-01 10:57   ` [PATCH v2 07/11] merge-octopus: rewrite in C Alban Gruin
2020-09-01 10:57   ` [PATCH v2 08/11] merge: use the "resolve" strategy without forking Alban Gruin
2020-09-01 10:57   ` [PATCH v2 09/11] merge: use the "octopus" " Alban Gruin
2020-09-01 10:57   ` [PATCH v2 10/11] sequencer: use the "resolve" " Alban Gruin
2020-09-01 10:57   ` [PATCH v2 11/11] sequencer: use the "octopus" merge " Alban Gruin
2020-10-05 12:26   ` [PATCH v3 00/11] Rewrite the remaining merge strategies from shell to C Alban Gruin
2020-10-05 12:26     ` [PATCH v3 01/11] t6027: modernise tests Alban Gruin
2020-10-06 20:50       ` Junio C Hamano
2020-10-05 12:26     ` [PATCH v3 02/11] merge-one-file: rewrite in C Alban Gruin
2020-10-06 22:01       ` Junio C Hamano
2020-10-21 19:47         ` Alban Gruin
2020-10-21 20:28           ` Junio C Hamano
2020-10-21 21:20             ` Junio C Hamano
2020-10-21 20:30           ` Junio C Hamano
2020-10-05 12:26     ` [PATCH v3 03/11] merge-index: libify merge_one_path() and merge_all() Alban Gruin
2020-10-09  4:48       ` Junio C Hamano
2020-11-06 19:53         ` Alban Gruin
2020-10-05 12:26     ` [PATCH v3 04/11] merge-index: don't fork if the requested program is `git-merge-one-file' Alban Gruin
2020-10-16 19:07       ` Junio C Hamano
2020-10-05 12:26     ` [PATCH v3 05/11] merge-resolve: rewrite in C Alban Gruin
2020-10-16 19:19       ` Junio C Hamano
2020-11-06 19:53         ` Alban Gruin
2020-10-05 12:26     ` [PATCH v3 06/11] merge-recursive: move better_branch_name() to merge.c Alban Gruin
2020-10-05 12:26     ` [PATCH v3 07/11] merge-octopus: rewrite in C Alban Gruin
2020-10-05 12:26     ` [PATCH v3 08/11] merge: use the "resolve" strategy without forking Alban Gruin
2020-10-05 12:26     ` [PATCH v3 09/11] merge: use the "octopus" " Alban Gruin
2020-10-05 12:26     ` [PATCH v3 10/11] sequencer: use the "resolve" " Alban Gruin
2020-10-05 12:26     ` [PATCH v3 11/11] sequencer: use the "octopus" merge " Alban Gruin
2020-10-07  6:57     ` [PATCH v3 00/11] Rewrite the remaining merge strategies from shell to C Johannes Schindelin
2020-11-13 11:04     ` [PATCH v4 00/12] " Alban Gruin
2020-11-13 11:04       ` [PATCH v4 01/12] t6027: modernise tests Alban Gruin
2020-11-13 11:04       ` [PATCH v4 02/12] update-index: move add_cacheinfo() to read-cache.c Alban Gruin
2020-11-13 11:04       ` [PATCH v4 03/12] merge-one-file: rewrite in C Alban Gruin
2020-11-13 11:04       ` [PATCH v4 04/12] merge-index: libify merge_one_path() and merge_all() Alban Gruin
2020-11-13 11:04       ` [PATCH v4 05/12] merge-index: don't fork if the requested program is `git-merge-one-file' Alban Gruin
2020-11-13 11:04       ` [PATCH v4 06/12] merge-resolve: rewrite in C Alban Gruin
2020-11-13 11:04       ` [PATCH v4 07/12] merge-recursive: move better_branch_name() to merge.c Alban Gruin
2020-11-13 11:04       ` [PATCH v4 08/12] merge-octopus: rewrite in C Alban Gruin
2020-11-13 11:04       ` [PATCH v4 09/12] merge: use the "resolve" strategy without forking Alban Gruin
2020-11-13 11:04       ` [PATCH v4 10/12] merge: use the "octopus" " Alban Gruin
2020-11-13 11:04       ` [PATCH v4 11/12] sequencer: use the "resolve" " Alban Gruin
2020-11-13 11:04       ` [PATCH v4 12/12] sequencer: use the "octopus" merge " Alban Gruin
2020-11-16 10:21       ` [PATCH v5 00/12] Rewrite the remaining merge strategies from shell to C Alban Gruin
2020-11-16 10:21         ` [PATCH v5 01/12] t6027: modernise tests Alban Gruin
2020-11-16 10:21         ` [PATCH v5 02/12] update-index: move add_cacheinfo() to read-cache.c Alban Gruin
2020-11-16 10:21         ` [PATCH v5 03/12] merge-one-file: rewrite in C Alban Gruin
2020-11-16 10:21         ` [PATCH v5 04/12] merge-index: libify merge_one_path() and merge_all() Alban Gruin
2020-11-16 10:21         ` [PATCH v5 05/12] merge-index: don't fork if the requested program is `git-merge-one-file' Alban Gruin
2020-11-16 10:21         ` [PATCH v5 06/12] merge-resolve: rewrite in C Alban Gruin
2020-11-16 10:21         ` [PATCH v5 07/12] merge-recursive: move better_branch_name() to merge.c Alban Gruin
2020-11-16 10:21         ` [PATCH v5 08/12] merge-octopus: rewrite in C Alban Gruin
2020-11-16 10:21         ` [PATCH v5 09/12] merge: use the "resolve" strategy without forking Alban Gruin
2020-11-16 10:21         ` [PATCH v5 10/12] merge: use the "octopus" " Alban Gruin
2020-11-16 10:21         ` [PATCH v5 11/12] sequencer: use the "resolve" " Alban Gruin
2020-11-16 10:21         ` [PATCH v5 12/12] sequencer: use the "octopus" merge " Alban Gruin
2020-11-24 11:53         ` [PATCH v6 00/13] Rewrite the remaining merge strategies from shell to C Alban Gruin
2020-11-24 11:53           ` [PATCH v6 01/13] t6407: modernise tests Alban Gruin
2020-11-24 11:53           ` [PATCH v6 02/13] t6060: modify multiple files to expose a possible issue with merge-index Alban Gruin
2020-11-24 11:53           ` [PATCH v6 03/13] update-index: move add_cacheinfo() to read-cache.c Alban Gruin
2020-12-22 20:54             ` Junio C Hamano
2020-11-24 11:53           ` [PATCH v6 04/13] merge-one-file: rewrite in C Alban Gruin
2020-12-22 21:36             ` Junio C Hamano
2021-01-03 22:41               ` Alban Gruin
2021-01-08  6:54                 ` Junio C Hamano
2020-11-24 11:53           ` [PATCH v6 05/13] merge-index: libify merge_one_path() and merge_all() Alban Gruin
2021-01-05 15:59             ` Derrick Stolee
2021-01-05 23:20               ` Alban Gruin
2020-11-24 11:53           ` [PATCH v6 06/13] merge-index: don't fork if the requested program is `git-merge-one-file' Alban Gruin
2021-01-05 16:11             ` Derrick Stolee
2021-01-05 17:35               ` Martin Ågren
2021-01-05 23:20                 ` Alban Gruin
2021-01-05 23:20               ` Alban Gruin
2021-01-06  2:04                 ` Junio C Hamano
2021-01-10 17:15                   ` Alban Gruin
2021-01-10 20:51                     ` Junio C Hamano
2021-03-08 20:32                       ` Alban Gruin
2020-11-24 11:53           ` [PATCH v6 07/13] merge-resolve: rewrite in C Alban Gruin
2020-11-24 11:53           ` [PATCH v6 08/13] merge-recursive: move better_branch_name() to merge.c Alban Gruin
2021-01-05 16:19             ` Derrick Stolee
2020-11-24 11:53           ` [PATCH v6 09/13] merge-octopus: rewrite in C Alban Gruin
2021-01-05 16:40             ` Derrick Stolee
2020-11-24 11:53           ` [PATCH v6 10/13] merge: use the "resolve" strategy without forking Alban Gruin
2021-01-05 16:45             ` Derrick Stolee
2020-11-24 11:53           ` [PATCH v6 11/13] merge: use the "octopus" " Alban Gruin
2020-11-24 11:53           ` [PATCH v6 12/13] sequencer: use the "resolve" " Alban Gruin
2020-11-24 11:53           ` [PATCH v6 13/13] sequencer: use the "octopus" merge " Alban Gruin
2020-11-24 19:34           ` [PATCH v6 00/13] Rewrite the remaining merge strategies from shell to C SZEDER Gábor
2021-01-05 16:50           ` Derrick Stolee
2021-03-17 20:49           ` [PATCH v7 00/15] " Alban Gruin
2021-03-17 20:49             ` [PATCH v7 01/15] t6407: modernise tests Alban Gruin
2021-03-17 20:49             ` [PATCH v7 02/15] t6060: modify multiple files to expose a possible issue with merge-index Alban Gruin
2021-03-17 20:49             ` [PATCH v7 03/15] t6060: add tests for removed files Alban Gruin
2021-03-22 21:36               ` Johannes Schindelin
2021-03-23 20:43                 ` Alban Gruin
2021-03-17 20:49             ` [PATCH v7 04/15] merge-index: libify merge_one_path() and merge_all() Alban Gruin
2021-03-17 20:49             ` [PATCH v7 05/15] merge-index: drop the index Alban Gruin
2021-03-17 20:49             ` [PATCH v7 06/15] merge-index: add a new way to invoke `git-merge-one-file' Alban Gruin
2021-03-17 20:49             ` [PATCH v7 07/15] update-index: move add_cacheinfo() to read-cache.c Alban Gruin
2021-03-22 21:59               ` Johannes Schindelin
2021-03-23 20:45                 ` Alban Gruin
2021-03-17 20:49             ` [PATCH v7 08/15] merge-one-file: rewrite in C Alban Gruin
2021-03-22 22:20               ` Johannes Schindelin
2021-03-23 20:53                 ` Alban Gruin [this message]
2021-03-24  9:10                   ` Johannes Schindelin
2021-04-10 14:17                     ` Alban Gruin
2021-03-17 20:49             ` [PATCH v7 09/15] merge-resolve: " Alban Gruin
2021-03-23 22:21               ` Johannes Schindelin
2021-04-10 14:17                 ` Alban Gruin
2021-03-17 20:49             ` [PATCH v7 10/15] merge-recursive: move better_branch_name() to merge.c Alban Gruin
2021-03-17 20:49             ` [PATCH v7 11/15] merge-octopus: rewrite in C Alban Gruin
2021-03-23 23:58               ` Johannes Schindelin
2021-03-17 20:49             ` [PATCH v7 12/15] merge: use the "resolve" strategy without forking Alban Gruin
2021-03-17 20:49             ` [PATCH v7 13/15] merge: use the "octopus" " Alban Gruin
2021-03-17 20:49             ` [PATCH v7 14/15] sequencer: use the "resolve" " Alban Gruin
2021-03-17 20:49             ` [PATCH v7 15/15] sequencer: use the "octopus" merge " Alban Gruin
2022-08-09 18:54             ` [PATCH v8 00/14] Rewrite the remaining merge strategies from shell to C Alban Gruin
2022-08-09 18:54               ` [PATCH v8 01/14] t6060: modify multiple files to expose a possible issue with merge-index Alban Gruin
2022-08-09 18:54               ` [PATCH v8 02/14] t6060: add tests for removed files Alban Gruin
2022-08-09 18:54               ` [PATCH v8 03/14] merge-index: libify merge_one_path() and merge_all() Alban Gruin
2022-08-09 18:54               ` [PATCH v8 04/14] merge-index: drop the index Alban Gruin
2022-08-09 18:54               ` [PATCH v8 05/14] merge-index: add a new way to invoke `git-merge-one-file' Alban Gruin
2022-08-09 21:36                 ` Johannes Schindelin
2022-08-09 18:54               ` [PATCH v8 06/14] update-index: move add_cacheinfo() to read-cache.c Alban Gruin
2022-08-09 18:54               ` [PATCH v8 07/14] merge-one-file: rewrite in C Alban Gruin
2022-08-09 22:01                 ` Johannes Schindelin
2022-08-09 18:54               ` [PATCH v8 08/14] merge-resolve: " Alban Gruin
2022-08-09 18:54               ` [PATCH v8 09/14] merge-recursive: move better_branch_name() to merge.c Alban Gruin
2022-08-09 18:54               ` [PATCH v8 10/14] merge-octopus: rewrite in C Alban Gruin
2022-08-09 18:54               ` [PATCH v8 11/14] merge: use the "resolve" strategy without forking Alban Gruin
2022-08-09 18:54               ` [PATCH v8 12/14] merge: use the "octopus" " Alban Gruin
2022-08-09 18:54               ` [PATCH v8 13/14] sequencer: use the "resolve" " Alban Gruin
2022-08-09 18:54               ` [PATCH v8 14/14] sequencer: use the "octopus" " Alban Gruin

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