diff mbox series

[v4,1/5] rebase -i: add --ignore-whitespace flag

Message ID 20200527173356.47364-2-phillip.wood123@gmail.com (mailing list archive)
State New, archived
Headers show
Series cleanup ra/rebase-i-more-options | expand

Commit Message

Phillip Wood May 27, 2020, 5:33 p.m. UTC
From: Rohit Ashiwal <rohit.ashiwal265@gmail.com>

Rebase is implemented with two different backends - 'apply' and 'merge'
each of which support a different set of options. In particuar the apply
backend supports a number of options implemented by 'git am' that are
not available to the merge backend. As part of an on going effort to
remove the apply backend this patch adds support for the
--ignore-whitespace option to the merge backend. This option treats
lines with only whitespace changes as unchanged and is implemented in
the merge backend by translating it to -Xignore-space-change.

Signed-off-by: Rohit Ashiwal <rohit.ashiwal265@gmail.com>
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
---
 Documentation/git-rebase.txt           | 19 +++++-
 builtin/rebase.c                       | 19 ++++--
 t/t3422-rebase-incompatible-options.sh |  1 -
 t/t3436-rebase-more-options.sh         | 86 ++++++++++++++++++++++++++
 4 files changed, 118 insertions(+), 7 deletions(-)
 create mode 100755 t/t3436-rebase-more-options.sh

Comments

Johannes Schindelin May 29, 2020, 2:38 a.m. UTC | #1
Hi Phillip,

sorry to be _so_ late in the game. (And sorry for sending this to you
twice, I managed to skip all the Cc:s due to the Reply-To: header the
first time round.)

On Wed, 27 May 2020, Phillip Wood wrote:

> From: Rohit Ashiwal <rohit.ashiwal265@gmail.com>
>
> Rebase is implemented with two different backends - 'apply' and 'merge'
> each of which support a different set of options. In particuar the apply
> backend supports a number of options implemented by 'git am' that are
> not available to the merge backend. As part of an on going effort to

As a non-native speaker, I am thrown off when reading "available to"
instead of the grammatically correct (I believe) "available in". Likewise,
"on going" instead of "ongoing" just disrupts my workflow.

Maybe these can be fixed?

> remove the apply backend this patch adds support for the
> --ignore-whitespace option to the merge backend. This option treats
> lines with only whitespace changes as unchanged and is implemented in
> the merge backend by translating it to -Xignore-space-change.
>
> Signed-off-by: Rohit Ashiwal <rohit.ashiwal265@gmail.com>
> Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
> ---
>  Documentation/git-rebase.txt           | 19 +++++-
>  builtin/rebase.c                       | 19 ++++--
>  t/t3422-rebase-incompatible-options.sh |  1 -
>  t/t3436-rebase-more-options.sh         | 86 ++++++++++++++++++++++++++
>  4 files changed, 118 insertions(+), 7 deletions(-)
>  create mode 100755 t/t3436-rebase-more-options.sh
>
> diff --git a/Documentation/git-rebase.txt b/Documentation/git-rebase.txt
> index f7a6033607..b003784f01 100644
> --- a/Documentation/git-rebase.txt
> +++ b/Documentation/git-rebase.txt
> @@ -422,8 +422,23 @@ your branch contains commits which were dropped, this option can be used
>  with `--keep-base` in order to drop those commits from your branch.
>
>  --ignore-whitespace::
> +	Ignore whitespace differences when trying to reconcile
> +differences. Currently, each backend implements an approximation of
> +this behavior:
> ++
> +apply backend: When applying a patch, ignore changes in whitespace in
> +context lines. Unfortunately, this means that if the "old" lines being
> +replaced by the patch differ only in whitespace from the existing
> +file, you will get a merge conflict instead of a successful patch
> +application.
> ++
> +merge backend: Treat lines with only whitespace changes as unchanged
> +when merging. Unfortunately, this means that any patch hunks that were
> +intended to modify whitespace and nothing else will be dropped, even
> +if the other side had no changes that conflicted.
> +
>  --whitespace=<option>::
> -	These flags are passed to the 'git apply' program
> +	This flag is passed to the 'git apply' program
>  	(see linkgit:git-apply[1]) that applies the patch.
>  	Implies --apply.
>  +
> @@ -572,7 +587,6 @@ The following options:
>   * --apply
>   * --committer-date-is-author-date
>   * --ignore-date
> - * --ignore-whitespace
>   * --whitespace
>   * -C
>
> @@ -598,6 +612,7 @@ In addition, the following pairs of options are incompatible:
>   * --preserve-merges and --signoff
>   * --preserve-merges and --rebase-merges
>   * --preserve-merges and --empty=
> + * --preserve-merges and --ignore-whitespace
>   * --keep-base and --onto
>   * --keep-base and --root
>
> diff --git a/builtin/rebase.c b/builtin/rebase.c
> index 27a07d4e78..5d8e117276 100644
> --- a/builtin/rebase.c
> +++ b/builtin/rebase.c
> @@ -86,6 +86,7 @@ struct rebase_options {
>  	int signoff;
>  	int allow_rerere_autoupdate;
>  	int autosquash;
> +	int ignore_whitespace;
>  	char *gpg_sign_opt;
>  	int autostash;
>  	char *cmd;
> @@ -108,6 +109,7 @@ struct rebase_options {
>
>  static struct replay_opts get_replay_opts(const struct rebase_options *opts)
>  {
> +	struct strbuf strategy_buf = STRBUF_INIT;
>  	struct replay_opts replay = REPLAY_OPTS_INIT;
>
>  	replay.action = REPLAY_INTERACTIVE_REBASE;
> @@ -126,14 +128,20 @@ static struct replay_opts get_replay_opts(const struct rebase_options *opts)
>  	replay.reschedule_failed_exec = opts->reschedule_failed_exec;
>  	replay.gpg_sign = xstrdup_or_null(opts->gpg_sign_opt);
>  	replay.strategy = opts->strategy;
> +
>  	if (opts->strategy_opts)
> -		parse_strategy_opts(&replay, opts->strategy_opts);
> +		strbuf_addstr(&strategy_buf, opts->strategy_opts);
> +	if (opts->ignore_whitespace)
> +		strbuf_addstr(&strategy_buf, " --ignore-space-change");
> +	if (strategy_buf.len)
> +		parse_strategy_opts(&replay, strategy_buf.buf);

Quite honestly, this is very, very ugly.

I would have expected this at a way earlier layer, namely in
`cmd__rebase()`. Something along these lines:

-- snip --
diff --git a/builtin/rebase.c b/builtin/rebase.c
index 37ba76ac3d26..748e08aee2f2 100644
--- a/builtin/rebase.c
+++ b/builtin/rebase.c
@@ -1289,6 +1289,7 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 	struct strbuf revisions = STRBUF_INIT;
 	struct strbuf buf = STRBUF_INIT;
 	struct object_id merge_base;
+	int ignore_whitespace = 0;
 	enum action action = ACTION_NONE;
 	const char *gpg_sign = NULL;
 	struct string_list exec = STRING_LIST_INIT_NODUP;
@@ -1318,9 +1319,8 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 			PARSE_OPT_NOARG, NULL, REBASE_DIFFSTAT },
 		OPT_BOOL(0, "signoff", &options.signoff,
 			 N_("add a Signed-off-by: line to each commit")),
-		OPT_PASSTHRU_ARGV(0, "ignore-whitespace", &options.git_am_opts,
-				  NULL, N_("passed to 'git am'"),
-				  PARSE_OPT_NOARG),
+		OPT_BOOL(0, "ignore-whitespace", &ignore_whitespace,
+			 N_("passed to 'git am'")),
 		OPT_PASSTHRU_ARGV(0, "committer-date-is-author-date",
 				  &options.git_am_opts, NULL,
 				  N_("passed to 'git am'"), PARSE_OPT_NOARG),
@@ -1682,6 +1682,15 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 		imply_merge(&options, "--rebase-merges");
 	}

+	if (ignore_whitespace) {
+		if (options.type == REBASE_APPLY)
+			argv_array_push(&options.git_am_opts,
+					"--ignore-whitespace");
+		else
+			string_list_append(&stragey_options,
+					   "--ignore-space-change");
+	}
+
 	if (strategy_options.nr) {
 		int i;

-- snap --


>
>  	if (opts->squash_onto) {
>  		oidcpy(&replay.squash_onto, opts->squash_onto);
>  		replay.have_squash_onto = 1;
>  	}
>
> +	strbuf_release(&strategy_buf);
>  	return replay;
>  }
>
> @@ -539,6 +547,8 @@ int cmd_rebase__interactive(int argc, const char **argv, const char *prefix)
>  	argc = parse_options(argc, argv, prefix, options,
>  			builtin_rebase_interactive_usage, PARSE_OPT_KEEP_ARGV0);
>
> +	opts.strategy_opts = xstrdup_or_null(opts.strategy_opts);

I am not sure what this is about: `opts.strategy_opts` is of type `char
*`, i.e. it is supposed to be already allocated.

Not that `cmd_rebase__interactive()` matters _all_ that much anymore, of
course: it is only used by the --preserve-merges backend, which will
hopefully be retired soon.

> +
>  	if (!is_null_oid(&squash_onto))
>  		opts.squash_onto = &squash_onto;
>
> @@ -991,6 +1001,8 @@ static int run_am(struct rebase_options *opts)
>  	am.git_cmd = 1;
>  	argv_array_push(&am.args, "am");
>
> +	if (opts->ignore_whitespace)
> +		argv_array_push(&am.args, "--ignore-whitespace");
>  	if (opts->action && !strcmp("continue", opts->action)) {
>  		argv_array_push(&am.args, "--resolved");
>  		argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
> @@ -1495,16 +1507,15 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
>  			PARSE_OPT_NOARG, NULL, REBASE_DIFFSTAT },
>  		OPT_BOOL(0, "signoff", &options.signoff,
>  			 N_("add a Signed-off-by: line to each commit")),
> -		OPT_PASSTHRU_ARGV(0, "ignore-whitespace", &options.git_am_opts,
> -				  NULL, N_("passed to 'git am'"),
> -				  PARSE_OPT_NOARG),
>  		OPT_PASSTHRU_ARGV(0, "committer-date-is-author-date",
>  				  &options.git_am_opts, NULL,
>  				  N_("passed to 'git am'"), PARSE_OPT_NOARG),
>  		OPT_PASSTHRU_ARGV(0, "ignore-date", &options.git_am_opts, NULL,
>  				  N_("passed to 'git am'"), PARSE_OPT_NOARG),
>  		OPT_PASSTHRU_ARGV('C', NULL, &options.git_am_opts, N_("n"),
>  				  N_("passed to 'git apply'"), 0),
> +		OPT_BOOL(0, "ignore-whitespace", &options.ignore_whitespace,
> +			 N_("ignore changes in whitespace")),
>  		OPT_PASSTHRU_ARGV(0, "whitespace", &options.git_am_opts,
>  				  N_("action"), N_("passed to 'git apply'"), 0),
>  		OPT_BIT('f', "force-rebase", &options.flags,
> diff --git a/t/t3422-rebase-incompatible-options.sh b/t/t3422-rebase-incompatible-options.sh
> index 50e7960702..55ca46786d 100755
> --- a/t/t3422-rebase-incompatible-options.sh
> +++ b/t/t3422-rebase-incompatible-options.sh
> @@ -61,7 +61,6 @@ test_rebase_am_only () {
>  }
>
>  test_rebase_am_only --whitespace=fix
> -test_rebase_am_only --ignore-whitespace
>  test_rebase_am_only --committer-date-is-author-date
>  test_rebase_am_only -C4
>
> diff --git a/t/t3436-rebase-more-options.sh b/t/t3436-rebase-more-options.sh
> new file mode 100755
> index 0000000000..fb5e747e86
> --- /dev/null
> +++ b/t/t3436-rebase-more-options.sh
> @@ -0,0 +1,86 @@
> +#!/bin/sh
> +#
> +# Copyright (c) 2019 Rohit Ashiwal
> +#
> +
> +test_description='tests to ensure compatibility between am and interactive backends'
> +
> +. ./test-lib.sh
> +
> +. "$TEST_DIRECTORY"/lib-rebase.sh
> +
> +# This is a special case in which both am and interactive backends
> +# provide the same output. It was done intentionally because
> +# both the backends fall short of optimal behaviour.
> +test_expect_success 'setup' '
> +	git checkout -b topic &&
> +	q_to_tab >file <<-\EOF &&
> +	line 1
> +	Qline 2
> +	line 3
> +	EOF
> +	git add file &&
> +	git commit -m "add file" &&
> +	cat >file <<-\EOF &&
> +	line 1
> +	new line 2
> +	line 3
> +	EOF
> +	git commit -am "update file" &&
> +	git tag side &&
> +
> +	git checkout --orphan master &&
> +	sed -e "s/^|//" >file <<-\EOF &&
> +	|line 1
> +	|        line 2
> +	|line 3
> +	EOF
> +	git add file &&
> +	git commit -m "add file" &&
> +	git tag main
> +'

The file contents are repeated in an awfully repetitive manner. That not
only makes things a bit hard to read, it also makes it all too easy to
slip in bugs by mistake. How about something like this instead?

	test_commit file &&

	test_write_lines line1 Qline2 line3 >templ &&

	q_to_tab <templ >file.t &&
	git commit -m tab file.t &&

	sed "s/Q/new /" <templ >file.t &&
	git commit -m new file.t &&
	git tag side &&

	git checkout file -- &&
	sed "s/Q/        /" <templ >file.t &&
	git commit -m spaces file.t

... and then...

> +
> +test_expect_success '--ignore-whitespace works with apply backend' '
> +	cat >expect <<-\EOF &&
> +	line 1
> +	new line 2
> +	line 3
> +	EOF

	sed "s/Q/new /" <templ >expect

> +	test_must_fail git rebase --apply main side &&
> +	git rebase --abort &&
> +	git rebase --apply --ignore-whitespace main side &&
> +	test_cmp expect file

Personally, I prefer to read the contents of `expect` directly before the
`test_cmp expect file.t`

> +'
> +
> +test_expect_success '--ignore-whitespace works with merge backend' '
> +	cat >expect <<-\EOF &&
> +	line 1
> +	new line 2
> +	line 3
> +	EOF

Isn't this totally identical to the `expect` constructed earlier? And in
any case, isn't this identical to `git show main:file.t`, which is what we
_actually_ expect: for the file contents to be identical to the tagged
`main`? I.e.

	git diff --exit-code main

> +	test_must_fail git rebase --merge main side &&
> +	git rebase --abort &&
> +	git rebase --merge --ignore-whitespace main side &&
> +	test_cmp expect file
> +'
> +
> +test_expect_success '--ignore-whitespace is remembered when continuing' '
> +	cat >expect <<-\EOF &&
> +	line 1
> +	new line 2
> +	line 3
> +	EOF
> +	(
> +		set_fake_editor &&
> +		FAKE_LINES="break 1" git rebase -i --ignore-whitespace main side
> +	) &&
> +	git rebase --continue &&
> +	test_cmp expect file

It is a bit funny to see these two invocations _specifically_ pulled out
from the subshell, that's not how we do things in other test scripts:
instead, we run all the Git commands _inside_ the subshell, and all the
verifications after the subshell.

I believe that with my suggestions, this test script will be a ton easier
to read and to maintain. At least it will be a lot DRYer.

Ciao,
Dscho

> +'
> +
> +# This must be the last test in this file
> +test_expect_success '$EDITOR and friends are unchanged' '
> +	test_editor_unchanged
> +'
> +
> +test_done
> --
> 2.26.2
>
>
Kerry, Richard June 1, 2020, 9:23 a.m. UTC | #2
As a non-native speaker, I am thrown off when reading "available to"
instead of the grammatically correct (I believe) "available in". Likewise, "on going" instead of "ongoing" just disrupts my workflow.

Maybe these can be fixed?

[RK] There is a distinct difference between "available to" and "available in".
[RK] "service A is available to entity B" does not mean the same as "service A is available in entity B".  The former indicates that service A is implemented within entity B, the latter indicates merely that entity B uses service A.
[RK] As a real world example consider "The internet banking service of Bank X is available to me", which makes complete sense.  But "The internet banking service of Bank X is available in me" would be nonsense.  I don't know what the OP intended but the difference between these is not purely grammatical, there is a difference in meaning which I must leave the OP to clarify.

[RK] As for the other issue, I too would suggest "ongoing".

[RK] Regards,
[RK] Richard.
Phillip Wood June 1, 2020, 10:26 a.m. UTC | #3
Hi dscho

Thanks for taking a look at this

On 29/05/2020 03:38, Johannes Schindelin wrote:
> Hi Phillip,
> 
> sorry to be _so_ late in the game. (And sorry for sending this to you
> twice, I managed to skip all the Cc:s due to the Reply-To: header the
> first time round.)
> 
> On Wed, 27 May 2020, Phillip Wood wrote:
> 
>> From: Rohit Ashiwal <rohit.ashiwal265@gmail.com>
>>
>> Rebase is implemented with two different backends - 'apply' and 'merge'
>> each of which support a different set of options. In particuar the apply
>> backend supports a number of options implemented by 'git am' that are
>> not available to the merge backend. As part of an on going effort to
> 
> As a non-native speaker, I am thrown off when reading "available to"
> instead of the grammatically correct (I believe) "available in". Likewise,
> "on going" instead of "ongoing" just disrupts my workflow.
> 
> Maybe these can be fixed?

Sure

>> diff --git a/builtin/rebase.c b/builtin/rebase.c
>> index 27a07d4e78..5d8e117276 100644
>> --- a/builtin/rebase.c
>> +++ b/builtin/rebase.c
>> @@ -86,6 +86,7 @@ struct rebase_options {
>>  	int signoff;
>>  	int allow_rerere_autoupdate;
>>  	int autosquash;
>> +	int ignore_whitespace;
>>  	char *gpg_sign_opt;
>>  	int autostash;
>>  	char *cmd;
>> @@ -108,6 +109,7 @@ struct rebase_options {
>>
>>  static struct replay_opts get_replay_opts(const struct rebase_options *opts)
>>  {
>> +	struct strbuf strategy_buf = STRBUF_INIT;
>>  	struct replay_opts replay = REPLAY_OPTS_INIT;
>>
>>  	replay.action = REPLAY_INTERACTIVE_REBASE;
>> @@ -126,14 +128,20 @@ static struct replay_opts get_replay_opts(const struct rebase_options *opts)
>>  	replay.reschedule_failed_exec = opts->reschedule_failed_exec;
>>  	replay.gpg_sign = xstrdup_or_null(opts->gpg_sign_opt);
>>  	replay.strategy = opts->strategy;
>> +
>>  	if (opts->strategy_opts)
>> -		parse_strategy_opts(&replay, opts->strategy_opts);
>> +		strbuf_addstr(&strategy_buf, opts->strategy_opts);
>> +	if (opts->ignore_whitespace)
>> +		strbuf_addstr(&strategy_buf, " --ignore-space-change");
>> +	if (strategy_buf.len)
>> +		parse_strategy_opts(&replay, strategy_buf.buf);
> 
> Quite honestly, this is very, very ugly.
> 
> I would have expected this at a way earlier layer, namely in
> `cmd__rebase()`. Something along these lines:

Yes your version is definitely better, I'll update with that (I had left
this patch mostly alone as unlike the later ones the original actually
worked)

> 
> -- snip --
> diff --git a/builtin/rebase.c b/builtin/rebase.c
> index 37ba76ac3d26..748e08aee2f2 100644
> --- a/builtin/rebase.c
> +++ b/builtin/rebase.c
> @@ -1289,6 +1289,7 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
>  	struct strbuf revisions = STRBUF_INIT;
>  	struct strbuf buf = STRBUF_INIT;
>  	struct object_id merge_base;
> +	int ignore_whitespace = 0;
>  	enum action action = ACTION_NONE;
>  	const char *gpg_sign = NULL;
>  	struct string_list exec = STRING_LIST_INIT_NODUP;
> @@ -1318,9 +1319,8 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
>  			PARSE_OPT_NOARG, NULL, REBASE_DIFFSTAT },
>  		OPT_BOOL(0, "signoff", &options.signoff,
>  			 N_("add a Signed-off-by: line to each commit")),
> -		OPT_PASSTHRU_ARGV(0, "ignore-whitespace", &options.git_am_opts,
> -				  NULL, N_("passed to 'git am'"),
> -				  PARSE_OPT_NOARG),
> +		OPT_BOOL(0, "ignore-whitespace", &ignore_whitespace,
> +			 N_("passed to 'git am'")),
>  		OPT_PASSTHRU_ARGV(0, "committer-date-is-author-date",
>  				  &options.git_am_opts, NULL,
>  				  N_("passed to 'git am'"), PARSE_OPT_NOARG),
> @@ -1682,6 +1682,15 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
>  		imply_merge(&options, "--rebase-merges");
>  	}
> 
> +	if (ignore_whitespace) {
> +		if (options.type == REBASE_APPLY)
> +			argv_array_push(&options.git_am_opts,
> +					"--ignore-whitespace");
> +		else
> +			string_list_append(&stragey_options,
> +					   "--ignore-space-change");
> +	}
> +
>  	if (strategy_options.nr) {
>  		int i;
> 
> -- snap --
> 
> 
>>
>>  	if (opts->squash_onto) {
>>  		oidcpy(&replay.squash_onto, opts->squash_onto);
>>  		replay.have_squash_onto = 1;
>>  	}
>>
>> +	strbuf_release(&strategy_buf);
>>  	return replay;
>>  }
>>
>> @@ -539,6 +547,8 @@ int cmd_rebase__interactive(int argc, const char **argv, const char *prefix)
>>  	argc = parse_options(argc, argv, prefix, options,
>>  			builtin_rebase_interactive_usage, PARSE_OPT_KEEP_ARGV0);
>>
>> +	opts.strategy_opts = xstrdup_or_null(opts.strategy_opts);
> 
> I am not sure what this is about: `opts.strategy_opts` is of type `char
> *`, i.e. it is supposed to be already allocated.
> 
> Not that `cmd_rebase__interactive()` matters _all_ that much anymore, of
> course: it is only used by the --preserve-merges backend, which will
> hopefully be retired soon.
> 
>> +
>>  	if (!is_null_oid(&squash_onto))
>>  		opts.squash_onto = &squash_onto;
>>
>> @@ -991,6 +1001,8 @@ static int run_am(struct rebase_options *opts)
>>  	am.git_cmd = 1;
>>  	argv_array_push(&am.args, "am");
>>
>> +	if (opts->ignore_whitespace)
>> +		argv_array_push(&am.args, "--ignore-whitespace");
>>  	if (opts->action && !strcmp("continue", opts->action)) {
>>  		argv_array_push(&am.args, "--resolved");
>>  		argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
>> @@ -1495,16 +1507,15 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
>>  			PARSE_OPT_NOARG, NULL, REBASE_DIFFSTAT },
>>  		OPT_BOOL(0, "signoff", &options.signoff,
>>  			 N_("add a Signed-off-by: line to each commit")),
>> -		OPT_PASSTHRU_ARGV(0, "ignore-whitespace", &options.git_am_opts,
>> -				  NULL, N_("passed to 'git am'"),
>> -				  PARSE_OPT_NOARG),
>>  		OPT_PASSTHRU_ARGV(0, "committer-date-is-author-date",
>>  				  &options.git_am_opts, NULL,
>>  				  N_("passed to 'git am'"), PARSE_OPT_NOARG),
>>  		OPT_PASSTHRU_ARGV(0, "ignore-date", &options.git_am_opts, NULL,
>>  				  N_("passed to 'git am'"), PARSE_OPT_NOARG),
>>  		OPT_PASSTHRU_ARGV('C', NULL, &options.git_am_opts, N_("n"),
>>  				  N_("passed to 'git apply'"), 0),
>> +		OPT_BOOL(0, "ignore-whitespace", &options.ignore_whitespace,
>> +			 N_("ignore changes in whitespace")),
>>  		OPT_PASSTHRU_ARGV(0, "whitespace", &options.git_am_opts,
>>  				  N_("action"), N_("passed to 'git apply'"), 0),
>>  		OPT_BIT('f', "force-rebase", &options.flags,
>> diff --git a/t/t3422-rebase-incompatible-options.sh b/t/t3422-rebase-incompatible-options.sh
>> index 50e7960702..55ca46786d 100755
>> --- a/t/t3422-rebase-incompatible-options.sh
>> +++ b/t/t3422-rebase-incompatible-options.sh
>> @@ -61,7 +61,6 @@ test_rebase_am_only () {
>>  }
>>
>>  test_rebase_am_only --whitespace=fix
>> -test_rebase_am_only --ignore-whitespace
>>  test_rebase_am_only --committer-date-is-author-date
>>  test_rebase_am_only -C4
>>
>> diff --git a/t/t3436-rebase-more-options.sh b/t/t3436-rebase-more-options.sh
>> new file mode 100755
>> index 0000000000..fb5e747e86
>> --- /dev/null
>> +++ b/t/t3436-rebase-more-options.sh
>> @@ -0,0 +1,86 @@
>> +#!/bin/sh
>> +#
>> +# Copyright (c) 2019 Rohit Ashiwal
>> +#
>> +
>> +test_description='tests to ensure compatibility between am and interactive backends'
>> +
>> +. ./test-lib.sh
>> +
>> +. "$TEST_DIRECTORY"/lib-rebase.sh
>> +
>> +# This is a special case in which both am and interactive backends
>> +# provide the same output. It was done intentionally because
>> +# both the backends fall short of optimal behaviour.
>> +test_expect_success 'setup' '
>> +	git checkout -b topic &&
>> +	q_to_tab >file <<-\EOF &&
>> +	line 1
>> +	Qline 2
>> +	line 3
>> +	EOF
>> +	git add file &&
>> +	git commit -m "add file" &&
>> +	cat >file <<-\EOF &&
>> +	line 1
>> +	new line 2
>> +	line 3
>> +	EOF
>> +	git commit -am "update file" &&
>> +	git tag side &&
>> +
>> +	git checkout --orphan master &&
>> +	sed -e "s/^|//" >file <<-\EOF &&
>> +	|line 1
>> +	|        line 2
>> +	|line 3
>> +	EOF
>> +	git add file &&
>> +	git commit -m "add file" &&
>> +	git tag main
>> +'
> 
> The file contents are repeated in an awfully repetitive manner. That not
> only makes things a bit hard to read, it also makes it all too easy to
> slip in bugs by mistake. How about something like this instead?
> 
> 	test_commit file &&
> 
> 	test_write_lines line1 Qline2 line3 >templ &&
> 
> 	q_to_tab <templ >file.t &&
> 	git commit -m tab file.t &&
> 
> 	sed "s/Q/new /" <templ >file.t &&
> 	git commit -m new file.t &&
> 	git tag side &&
> 
> 	git checkout file -- &&
> 	sed "s/Q/        /" <templ >file.t &&
> 	git commit -m spaces file.t

I'm not totally convinced by this, I'd prefer to be able to read the
contents rather than having to work out what sed is doing. What about

test_write_lines "line 1" "	line 2" "line 3" >file &&
add and commit
test_write_lines "line 1" "new line 2" "line 3" >file &&
commit and tag
test_write_lines "line 1" "  line 2" "line 3" >file &&
commit and tag

It does not get rid of the repetition but it does dispense with having
the work out what sed and q_to_tab are doing

> ... and then...
> 
>> +
>> +test_expect_success '--ignore-whitespace works with apply backend' '
>> +	cat >expect <<-\EOF &&
>> +	line 1
>> +	new line 2
>> +	line 3
>> +	EOF
> 
> 	sed "s/Q/new /" <templ >expect
> 
>> +	test_must_fail git rebase --apply main side &&
>> +	git rebase --abort &&
>> +	git rebase --apply --ignore-whitespace main side &&
>> +	test_cmp expect file
> 
> Personally, I prefer to read the contents of `expect` directly before the
> `test_cmp expect file.t`

I can move it but if we use sed you cannot see the contents

>> +'
>> +
>> +test_expect_success '--ignore-whitespace works with merge backend' '
>> +	cat >expect <<-\EOF &&
>> +	line 1
>> +	new line 2
>> +	line 3
>> +	EOF
> 
> Isn't this totally identical to the `expect` constructed earlier? And in
> any case, isn't this identical to `git show main:file.t`, which is what we
> _actually_ expect: for the file contents to be identical to the tagged
> `main`? I.e.

Well spotted I'll update (I think it's actually the same as side)

> 	git diff --exit-code main
> 
>> +	test_must_fail git rebase --merge main side &&
>> +	git rebase --abort &&
>> +	git rebase --merge --ignore-whitespace main side &&
>> +	test_cmp expect file
>> +'
>> +
>> +test_expect_success '--ignore-whitespace is remembered when continuing' '
>> +	cat >expect <<-\EOF &&
>> +	line 1
>> +	new line 2
>> +	line 3
>> +	EOF
>> +	(
>> +		set_fake_editor &&
>> +		FAKE_LINES="break 1" git rebase -i --ignore-whitespace main side
>> +	) &&
>> +	git rebase --continue &&
>> +	test_cmp expect file
> 
> It is a bit funny to see these two invocations _specifically_ pulled out
> from the subshell, that's not how we do things in other test scripts:
> instead, we run all the Git commands _inside_ the subshell, and all the
> verifications after the subshell.

The idea was to only set the variable where it is used.

Best Wishes

Phillip

> I believe that with my suggestions, this test script will be a ton easier
> to read and to maintain. At least it will be a lot DRYer.
> 
> Ciao,
> Dscho
> 
>> +'
>> +
>> +# This must be the last test in this file
>> +test_expect_success '$EDITOR and friends are unchanged' '
>> +	test_editor_unchanged
>> +'
>> +
>> +test_done
>> --
>> 2.26.2
>>
>>
Johannes Schindelin June 1, 2020, 9:03 p.m. UTC | #4
Hi Phillip,

On Mon, 1 Jun 2020, Phillip Wood wrote:

> On 29/05/2020 03:38, Johannes Schindelin wrote:
> >
> > On Wed, 27 May 2020, Phillip Wood wrote:
> >
> >> From: Rohit Ashiwal <rohit.ashiwal265@gmail.com>
> >>
> >> [...]
> >> diff --git a/t/t3436-rebase-more-options.sh b/t/t3436-rebase-more-options.sh
> >> new file mode 100755
> >> index 0000000000..fb5e747e86
> >> --- /dev/null
> >> +++ b/t/t3436-rebase-more-options.sh
> >> @@ -0,0 +1,86 @@
> >> +#!/bin/sh
> >> +#
> >> +# Copyright (c) 2019 Rohit Ashiwal
> >> +#
> >> +
> >> +test_description='tests to ensure compatibility between am and interactive backends'
> >> +
> >> +. ./test-lib.sh
> >> +
> >> +. "$TEST_DIRECTORY"/lib-rebase.sh
> >> +
> >> +# This is a special case in which both am and interactive backends
> >> +# provide the same output. It was done intentionally because
> >> +# both the backends fall short of optimal behaviour.
> >> +test_expect_success 'setup' '
> >> +	git checkout -b topic &&
> >> +	q_to_tab >file <<-\EOF &&
> >> +	line 1
> >> +	Qline 2
> >> +	line 3
> >> +	EOF
> >> +	git add file &&
> >> +	git commit -m "add file" &&
> >> +	cat >file <<-\EOF &&
> >> +	line 1
> >> +	new line 2
> >> +	line 3
> >> +	EOF
> >> +	git commit -am "update file" &&
> >> +	git tag side &&
> >> +
> >> +	git checkout --orphan master &&
> >> +	sed -e "s/^|//" >file <<-\EOF &&
> >> +	|line 1
> >> +	|        line 2
> >> +	|line 3
> >> +	EOF
> >> +	git add file &&
> >> +	git commit -m "add file" &&
> >> +	git tag main
> >> +'
> >
> > The file contents are repeated in an awfully repetitive manner. That not
> > only makes things a bit hard to read, it also makes it all too easy to
> > slip in bugs by mistake. How about something like this instead?
> >
> > 	test_commit file &&
> >
> > 	test_write_lines line1 Qline2 line3 >templ &&
> >
> > 	q_to_tab <templ >file.t &&
> > 	git commit -m tab file.t &&
> >
> > 	sed "s/Q/new /" <templ >file.t &&
> > 	git commit -m new file.t &&
> > 	git tag side &&
> >
> > 	git checkout file -- &&
> > 	sed "s/Q/        /" <templ >file.t &&
> > 	git commit -m spaces file.t
>
> I'm not totally convinced by this, I'd prefer to be able to read the
> contents rather than having to work out what sed is doing. What about
>
> test_write_lines "line 1" "	line 2" "line 3" >file &&
> add and commit
> test_write_lines "line 1" "new line 2" "line 3" >file &&
> commit and tag
> test_write_lines "line 1" "  line 2" "line 3" >file &&
> commit and tag
>
> It does not get rid of the repetition but it does dispense with having
> the work out what sed and q_to_tab are doing

Sure. Your version is still tons easier to parse for a human being.

> > 	git diff --exit-code main
> >
> >> +	test_must_fail git rebase --merge main side &&
> >> +	git rebase --abort &&
> >> +	git rebase --merge --ignore-whitespace main side &&
> >> +	test_cmp expect file
> >> +'
> >> +
> >> +test_expect_success '--ignore-whitespace is remembered when continuing' '
> >> +	cat >expect <<-\EOF &&
> >> +	line 1
> >> +	new line 2
> >> +	line 3
> >> +	EOF
> >> +	(
> >> +		set_fake_editor &&
> >> +		FAKE_LINES="break 1" git rebase -i --ignore-whitespace main side
> >> +	) &&
> >> +	git rebase --continue &&
> >> +	test_cmp expect file
> >
> > It is a bit funny to see these two invocations _specifically_ pulled out
> > from the subshell, that's not how we do things in other test scripts:
> > instead, we run all the Git commands _inside_ the subshell, and all the
> > verifications after the subshell.
>
> The idea was to only set the variable where it is used.

I understand that, but I think that it would be better to follow the
existing pattern rather than introducing an inconsistent second one.

Thanks,
Dscho
diff mbox series

Patch

diff --git a/Documentation/git-rebase.txt b/Documentation/git-rebase.txt
index f7a6033607..b003784f01 100644
--- a/Documentation/git-rebase.txt
+++ b/Documentation/git-rebase.txt
@@ -422,8 +422,23 @@  your branch contains commits which were dropped, this option can be used
 with `--keep-base` in order to drop those commits from your branch.
 
 --ignore-whitespace::
+	Ignore whitespace differences when trying to reconcile
+differences. Currently, each backend implements an approximation of
+this behavior:
++
+apply backend: When applying a patch, ignore changes in whitespace in
+context lines. Unfortunately, this means that if the "old" lines being
+replaced by the patch differ only in whitespace from the existing
+file, you will get a merge conflict instead of a successful patch
+application.
++
+merge backend: Treat lines with only whitespace changes as unchanged
+when merging. Unfortunately, this means that any patch hunks that were
+intended to modify whitespace and nothing else will be dropped, even
+if the other side had no changes that conflicted.
+
 --whitespace=<option>::
-	These flags are passed to the 'git apply' program
+	This flag is passed to the 'git apply' program
 	(see linkgit:git-apply[1]) that applies the patch.
 	Implies --apply.
 +
@@ -572,7 +587,6 @@  The following options:
  * --apply
  * --committer-date-is-author-date
  * --ignore-date
- * --ignore-whitespace
  * --whitespace
  * -C
 
@@ -598,6 +612,7 @@  In addition, the following pairs of options are incompatible:
  * --preserve-merges and --signoff
  * --preserve-merges and --rebase-merges
  * --preserve-merges and --empty=
+ * --preserve-merges and --ignore-whitespace
  * --keep-base and --onto
  * --keep-base and --root
 
diff --git a/builtin/rebase.c b/builtin/rebase.c
index 27a07d4e78..5d8e117276 100644
--- a/builtin/rebase.c
+++ b/builtin/rebase.c
@@ -86,6 +86,7 @@  struct rebase_options {
 	int signoff;
 	int allow_rerere_autoupdate;
 	int autosquash;
+	int ignore_whitespace;
 	char *gpg_sign_opt;
 	int autostash;
 	char *cmd;
@@ -108,6 +109,7 @@  struct rebase_options {
 
 static struct replay_opts get_replay_opts(const struct rebase_options *opts)
 {
+	struct strbuf strategy_buf = STRBUF_INIT;
 	struct replay_opts replay = REPLAY_OPTS_INIT;
 
 	replay.action = REPLAY_INTERACTIVE_REBASE;
@@ -126,14 +128,20 @@  static struct replay_opts get_replay_opts(const struct rebase_options *opts)
 	replay.reschedule_failed_exec = opts->reschedule_failed_exec;
 	replay.gpg_sign = xstrdup_or_null(opts->gpg_sign_opt);
 	replay.strategy = opts->strategy;
+
 	if (opts->strategy_opts)
-		parse_strategy_opts(&replay, opts->strategy_opts);
+		strbuf_addstr(&strategy_buf, opts->strategy_opts);
+	if (opts->ignore_whitespace)
+		strbuf_addstr(&strategy_buf, " --ignore-space-change");
+	if (strategy_buf.len)
+		parse_strategy_opts(&replay, strategy_buf.buf);
 
 	if (opts->squash_onto) {
 		oidcpy(&replay.squash_onto, opts->squash_onto);
 		replay.have_squash_onto = 1;
 	}
 
+	strbuf_release(&strategy_buf);
 	return replay;
 }
 
@@ -539,6 +547,8 @@  int cmd_rebase__interactive(int argc, const char **argv, const char *prefix)
 	argc = parse_options(argc, argv, prefix, options,
 			builtin_rebase_interactive_usage, PARSE_OPT_KEEP_ARGV0);
 
+	opts.strategy_opts = xstrdup_or_null(opts.strategy_opts);
+
 	if (!is_null_oid(&squash_onto))
 		opts.squash_onto = &squash_onto;
 
@@ -991,6 +1001,8 @@  static int run_am(struct rebase_options *opts)
 	am.git_cmd = 1;
 	argv_array_push(&am.args, "am");
 
+	if (opts->ignore_whitespace)
+		argv_array_push(&am.args, "--ignore-whitespace");
 	if (opts->action && !strcmp("continue", opts->action)) {
 		argv_array_push(&am.args, "--resolved");
 		argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
@@ -1495,16 +1507,15 @@  int cmd_rebase(int argc, const char **argv, const char *prefix)
 			PARSE_OPT_NOARG, NULL, REBASE_DIFFSTAT },
 		OPT_BOOL(0, "signoff", &options.signoff,
 			 N_("add a Signed-off-by: line to each commit")),
-		OPT_PASSTHRU_ARGV(0, "ignore-whitespace", &options.git_am_opts,
-				  NULL, N_("passed to 'git am'"),
-				  PARSE_OPT_NOARG),
 		OPT_PASSTHRU_ARGV(0, "committer-date-is-author-date",
 				  &options.git_am_opts, NULL,
 				  N_("passed to 'git am'"), PARSE_OPT_NOARG),
 		OPT_PASSTHRU_ARGV(0, "ignore-date", &options.git_am_opts, NULL,
 				  N_("passed to 'git am'"), PARSE_OPT_NOARG),
 		OPT_PASSTHRU_ARGV('C', NULL, &options.git_am_opts, N_("n"),
 				  N_("passed to 'git apply'"), 0),
+		OPT_BOOL(0, "ignore-whitespace", &options.ignore_whitespace,
+			 N_("ignore changes in whitespace")),
 		OPT_PASSTHRU_ARGV(0, "whitespace", &options.git_am_opts,
 				  N_("action"), N_("passed to 'git apply'"), 0),
 		OPT_BIT('f', "force-rebase", &options.flags,
diff --git a/t/t3422-rebase-incompatible-options.sh b/t/t3422-rebase-incompatible-options.sh
index 50e7960702..55ca46786d 100755
--- a/t/t3422-rebase-incompatible-options.sh
+++ b/t/t3422-rebase-incompatible-options.sh
@@ -61,7 +61,6 @@  test_rebase_am_only () {
 }
 
 test_rebase_am_only --whitespace=fix
-test_rebase_am_only --ignore-whitespace
 test_rebase_am_only --committer-date-is-author-date
 test_rebase_am_only -C4
 
diff --git a/t/t3436-rebase-more-options.sh b/t/t3436-rebase-more-options.sh
new file mode 100755
index 0000000000..fb5e747e86
--- /dev/null
+++ b/t/t3436-rebase-more-options.sh
@@ -0,0 +1,86 @@ 
+#!/bin/sh
+#
+# Copyright (c) 2019 Rohit Ashiwal
+#
+
+test_description='tests to ensure compatibility between am and interactive backends'
+
+. ./test-lib.sh
+
+. "$TEST_DIRECTORY"/lib-rebase.sh
+
+# This is a special case in which both am and interactive backends
+# provide the same output. It was done intentionally because
+# both the backends fall short of optimal behaviour.
+test_expect_success 'setup' '
+	git checkout -b topic &&
+	q_to_tab >file <<-\EOF &&
+	line 1
+	Qline 2
+	line 3
+	EOF
+	git add file &&
+	git commit -m "add file" &&
+	cat >file <<-\EOF &&
+	line 1
+	new line 2
+	line 3
+	EOF
+	git commit -am "update file" &&
+	git tag side &&
+
+	git checkout --orphan master &&
+	sed -e "s/^|//" >file <<-\EOF &&
+	|line 1
+	|        line 2
+	|line 3
+	EOF
+	git add file &&
+	git commit -m "add file" &&
+	git tag main
+'
+
+test_expect_success '--ignore-whitespace works with apply backend' '
+	cat >expect <<-\EOF &&
+	line 1
+	new line 2
+	line 3
+	EOF
+	test_must_fail git rebase --apply main side &&
+	git rebase --abort &&
+	git rebase --apply --ignore-whitespace main side &&
+	test_cmp expect file
+'
+
+test_expect_success '--ignore-whitespace works with merge backend' '
+	cat >expect <<-\EOF &&
+	line 1
+	new line 2
+	line 3
+	EOF
+	test_must_fail git rebase --merge main side &&
+	git rebase --abort &&
+	git rebase --merge --ignore-whitespace main side &&
+	test_cmp expect file
+'
+
+test_expect_success '--ignore-whitespace is remembered when continuing' '
+	cat >expect <<-\EOF &&
+	line 1
+	new line 2
+	line 3
+	EOF
+	(
+		set_fake_editor &&
+		FAKE_LINES="break 1" git rebase -i --ignore-whitespace main side
+	) &&
+	git rebase --continue &&
+	test_cmp expect file
+'
+
+# This must be the last test in this file
+test_expect_success '$EDITOR and friends are unchanged' '
+	test_editor_unchanged
+'
+
+test_done