[PATCH v2] pathspec: honor `PATHSPEC_PREFIX_ORIGIN` with empty prefix

[PATCH v2] pathspec: honor `PATHSPEC_PREFIX_ORIGIN` with empty prefix

[Patrick Steinhardt]

Previous to commit 5d8f084a5 (pathspec: simpler logic to prefix original
pathspec elements, 2017-01-04), we were always using the computed
`match` variable to perform pathspec matching whenever
`PATHSPEC_PREFIX_ORIGIN` is set. This is for example useful when passing
the parsed pathspecs to other commands, as the computed `match` may
contain a pathspec relative to the repository root. The commit changed
this logic to only do so when we do have an actual prefix and when
literal pathspecs are deactivated.

But this change may actually break some commands which expect passed
pathspecs to be relative to the repository root. One such case is `git
add --patch`, which now fails when using relative paths from a
subdirectory. For example if executing "git add -p ../foo.c" in a
subdirectory, the `git-add--interactive` command will directly pass
"../foo.c" to `git-ls-files`. As ls-files is executed at the
repository's root, the command will notice that "../foo.c" is outside
the repository and fail.

Fix the issue by again using the computed `match` variable when
`PATHSPEC_PREFIX_ORIGIN` is set and global literal pathspecs are
deactivated. Note that in contrast to previous behavior, we will now
always call `prefix_magic` regardless of whether a prefix is actually
set. But this is the right thing to do: when the `match` variable has
been resolved to the repository's root, it will be set to an empty
string. When passing the empty string directly to other commands, it
will result in a warning regarding deprecated empty pathspecs. By always
adding the prefix magic, we will end up with at least the string
":(prefix:0)" and thus avoid the warning.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
---

This is the second version of [1]. It fixes a bug catched by
Brandon when the pathspec is resolved to the empty string and
improves the test a bit to actually catch this issue.

[1]: http://public-inbox.org/git/1556910880cfce391bdca2d8f0cbcb8c71371691.1491206540.git.ps@pks.im/T/#u


 pathspec.c                 |  2 +-
 t/t3701-add-interactive.sh | 22 ++++++++++++++++++++++
 2 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/pathspec.c b/pathspec.c
index 303efda83..3079a817a 100644
--- a/pathspec.c
+++ b/pathspec.c
@@ -505,7 +505,7 @@ static void init_pathspec_item(struct pathspec_item *item, unsigned flags,
 	 * original. Useful for passing to another command.
 	 */
 	if ((flags & PATHSPEC_PREFIX_ORIGIN) &&
-	    prefixlen && !get_literal_global()) {
+	    !get_literal_global()) {
 		struct strbuf sb = STRBUF_INIT;
 
 		/* Preserve the actual prefix length of each pattern */
diff --git a/t/t3701-add-interactive.sh b/t/t3701-add-interactive.sh
index f9528fa00..2ecb43a61 100755
--- a/t/t3701-add-interactive.sh
+++ b/t/t3701-add-interactive.sh
@@ -436,6 +436,28 @@ test_expect_success 'add -p handles globs' '
 	test_cmp expect actual
 '
 
+test_expect_success 'add -p handles relative paths' '
+	git reset --hard &&
+
+	echo base >relpath.c &&
+	git add "*.c" &&
+	git commit -m relpath &&
+
+	echo change >relpath.c &&
+	mkdir -p subdir &&
+	git -C subdir add -p .. 2>error <<-\EOF &&
+	y
+	EOF
+
+	test_must_be_empty error &&
+
+	cat >expect <<-\EOF &&
+	relpath.c
+	EOF
+	git diff --cached --name-only >actual &&
+	test_cmp expect actual
+'
+
 test_expect_success 'add -p does not expand argument lists' '
 	git reset --hard &&
 
-- 
2.12.2

Re: [PATCH v2] pathspec: honor `PATHSPEC_PREFIX_ORIGIN` with empty prefix

[Brandon Williams]

On 04/04, Patrick Steinhardt wrote:
> Previous to commit 5d8f084a5 (pathspec: simpler logic to prefix original
> pathspec elements, 2017-01-04), we were always using the computed
> `match` variable to perform pathspec matching whenever
> `PATHSPEC_PREFIX_ORIGIN` is set. This is for example useful when passing
> the parsed pathspecs to other commands, as the computed `match` may
> contain a pathspec relative to the repository root. The commit changed
> this logic to only do so when we do have an actual prefix and when
> literal pathspecs are deactivated.
> 
> But this change may actually break some commands which expect passed
> pathspecs to be relative to the repository root. One such case is `git
> add --patch`, which now fails when using relative paths from a
> subdirectory. For example if executing "git add -p ../foo.c" in a
> subdirectory, the `git-add--interactive` command will directly pass
> "../foo.c" to `git-ls-files`. As ls-files is executed at the
> repository's root, the command will notice that "../foo.c" is outside
> the repository and fail.
> 
> Fix the issue by again using the computed `match` variable when
> `PATHSPEC_PREFIX_ORIGIN` is set and global literal pathspecs are
> deactivated. Note that in contrast to previous behavior, we will now
> always call `prefix_magic` regardless of whether a prefix is actually
> set. But this is the right thing to do: when the `match` variable has
> been resolved to the repository's root, it will be set to an empty
> string. When passing the empty string directly to other commands, it
> will result in a warning regarding deprecated empty pathspecs. By always
> adding the prefix magic, we will end up with at least the string
> ":(prefix:0)" and thus avoid the warning.
> 
> Signed-off-by: Patrick Steinhardt <ps@pks.im>
> ---
> 
> This is the second version of [1]. It fixes a bug catched by
> Brandon when the pathspec is resolved to the empty string and
> improves the test a bit to actually catch this issue.

This version looks good to me.  Thanks for fixing that small issue!

-- 
Brandon Williams

Re: [PATCH v2] pathspec: honor `PATHSPEC_PREFIX_ORIGIN` with empty prefix

[Duy Nguyen]

On Tue, Apr 4, 2017 at 11:39 PM, Brandon Williams <bmwill@google.com> wrote:
>> This is the second version of [1]. It fixes a bug catched by
>> Brandon when the pathspec is resolved to the empty string and
>> improves the test a bit to actually catch this issue.
>
> This version looks good to me.  Thanks for fixing that small issue!

Looks good to me too (I didn't see this when I read v1, too much mails)
-- 
Duy

Re: [PATCH v2] pathspec: honor `PATHSPEC_PREFIX_ORIGIN` with empty prefix

[Patrick Steinhardt]

[-- Attachment #1: Type: text/plain, Size: 3912 bytes --]

On Tue, Apr 04, 2017 at 11:16:56AM +0200, Patrick Steinhardt wrote:
> Previous to commit 5d8f084a5 (pathspec: simpler logic to prefix original
> pathspec elements, 2017-01-04), we were always using the computed
> `match` variable to perform pathspec matching whenever
> `PATHSPEC_PREFIX_ORIGIN` is set. This is for example useful when passing
> the parsed pathspecs to other commands, as the computed `match` may
> contain a pathspec relative to the repository root. The commit changed
> this logic to only do so when we do have an actual prefix and when
> literal pathspecs are deactivated.
> 
> But this change may actually break some commands which expect passed
> pathspecs to be relative to the repository root. One such case is `git
> add --patch`, which now fails when using relative paths from a
> subdirectory. For example if executing "git add -p ../foo.c" in a
> subdirectory, the `git-add--interactive` command will directly pass
> "../foo.c" to `git-ls-files`. As ls-files is executed at the
> repository's root, the command will notice that "../foo.c" is outside
> the repository and fail.
> 
> Fix the issue by again using the computed `match` variable when
> `PATHSPEC_PREFIX_ORIGIN` is set and global literal pathspecs are
> deactivated. Note that in contrast to previous behavior, we will now
> always call `prefix_magic` regardless of whether a prefix is actually
> set. But this is the right thing to do: when the `match` variable has
> been resolved to the repository's root, it will be set to an empty
> string. When passing the empty string directly to other commands, it
> will result in a warning regarding deprecated empty pathspecs. By always
> adding the prefix magic, we will end up with at least the string
> ":(prefix:0)" and thus avoid the warning.
> 
> Signed-off-by: Patrick Steinhardt <ps@pks.im>
> ---

Just a short reminder on this patch, as I haven't seen it or
v1 being picked up by the What's Cooking reports. Am I simply
being too eager or was this an oversight?

Thanks
Patrick

> 
> This is the second version of [1]. It fixes a bug catched by
> Brandon when the pathspec is resolved to the empty string and
> improves the test a bit to actually catch this issue.
> 
> [1]: http://public-inbox.org/git/1556910880cfce391bdca2d8f0cbcb8c71371691.1491206540.git.ps@pks.im/T/#u
> 
> 
>  pathspec.c                 |  2 +-
>  t/t3701-add-interactive.sh | 22 ++++++++++++++++++++++
>  2 files changed, 23 insertions(+), 1 deletion(-)
> 
> diff --git a/pathspec.c b/pathspec.c
> index 303efda83..3079a817a 100644
> --- a/pathspec.c
> +++ b/pathspec.c
> @@ -505,7 +505,7 @@ static void init_pathspec_item(struct pathspec_item *item, unsigned flags,
>  	 * original. Useful for passing to another command.
>  	 */
>  	if ((flags & PATHSPEC_PREFIX_ORIGIN) &&
> -	    prefixlen && !get_literal_global()) {
> +	    !get_literal_global()) {
>  		struct strbuf sb = STRBUF_INIT;
>  
>  		/* Preserve the actual prefix length of each pattern */
> diff --git a/t/t3701-add-interactive.sh b/t/t3701-add-interactive.sh
> index f9528fa00..2ecb43a61 100755
> --- a/t/t3701-add-interactive.sh
> +++ b/t/t3701-add-interactive.sh
> @@ -436,6 +436,28 @@ test_expect_success 'add -p handles globs' '
>  	test_cmp expect actual
>  '
>  
> +test_expect_success 'add -p handles relative paths' '
> +	git reset --hard &&
> +
> +	echo base >relpath.c &&
> +	git add "*.c" &&
> +	git commit -m relpath &&
> +
> +	echo change >relpath.c &&
> +	mkdir -p subdir &&
> +	git -C subdir add -p .. 2>error <<-\EOF &&
> +	y
> +	EOF
> +
> +	test_must_be_empty error &&
> +
> +	cat >expect <<-\EOF &&
> +	relpath.c
> +	EOF
> +	git diff --cached --name-only >actual &&
> +	test_cmp expect actual
> +'
> +
>  test_expect_success 'add -p does not expand argument lists' '
>  	git reset --hard &&
>  
> -- 
> 2.12.2

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Re: [PATCH v2] pathspec: honor `PATHSPEC_PREFIX_ORIGIN` with empty prefix

[Junio C Hamano]

Patrick Steinhardt <ps@pks.im> writes:

> Just a short reminder on this patch, as I haven't seen it or
> v1 being picked up by the What's Cooking reports. Am I simply
> being too eager or was this an oversight?

I have been offline and will be for a few more days; I may
occasionally pop in to give design level guidance on topics, but
won't be reading patches carefully enough to queue a new topic to my
tree.  New topics won't be added to my tree until next week the
earliest.