threads / bug / 46293

Bug with automated processing of git status results

Subject: Bug with automated processing of git status results

## tl;dr

9 messages between Jun 30, 2017 and Jul 5, 2017.

replies: 8people: 7as markdown or json

Сергей Шестаков· Jun 30, 2017, 06:00 UTC · lore
Hi!

I am trying to make an automated processing of "git status" results. I execute the command

git status -z -uno

I expect that it has stable output format. However, it still can print warnings like

warning: CRLF will be replaced by LF in somefile.xml

I understand that we can turn off core.safecrlf, but it's inconvinient. It would be better if "git status" command had an optional parameter that disables any other output besides changed files.

Thanks! Sergey Shestakov Playrix

Konstantin Khomoutov· Jun 30, 2017, 07:12 UTC · re: Сергей Шестаков · lore

Re: Bug with automated processing of git status results

On Fri, Jun 30, 2017 at 09:00:14AM +0300, Сергей Шестаков wrote:
Show 14 quoted lines
> I am trying to make an automated processing of "git status" results.
> I execute the command
> 
> git status -z -uno
> 
> I expect that it has stable output format. However, it still can print
> warnings like
> 
> warning: CRLF will be replaced by LF in somefile.xml
> 
> I understand that we can turn off core.safecrlf, but it's
> inconvinient. It would be better if "git status" command had an
> optional parameter that disables any other output besides changed
> files.

The `git status` command supposedly writes their "regular" data to its standard output while warnings go to its standard error stream. Is this not the case?

Matthieu Moy· Jun 30, 2017, 09:09 UTC · re: Сергей Шестаков · lore

Re: Bug with automated processing of git status results

Сергей Шестаков <s_shestakov@playrix.com> writes:
> I understand that we can turn off core.safecrlf, but it's
> inconvinient.
Note that you can do that without actually changing the config file:
  git -c core.safecrlf=false status ...
-- 
Matthieu Moy
http://www-verimag.imag.fr/~moy/
Torsten Bögershausen· Jun 30, 2017, 09:22 UTC · re: Matthieu Moy · lore

Re: Bug with automated processing of git status results

On 30/06/17 11:09, Matthieu Moy wrote:
Show 9 quoted lines
> Сергей Шестаков <s_shestakov@playrix.com> writes:
> 
>> I understand that we can turn off core.safecrlf, but it's
>> inconvinient.
> 
> Note that you can do that without actually changing the config file:
> 
>    git -c core.safecrlf=false status ...
> 
Beside that, I would recommend to set up a .gitattributes file:

$ echo "*.xml text eol=lf" >>.gitattributes $ git add .gitattributes $ git commit -m "xml files are text with LF line endings"

Stefan Beller· Jun 30, 2017, 16:28 UTC · re: Torsten Bögershausen · lore

[PATCH] status: suppress additional warning output in plumbing modes

When status is called with '--porcelain' (as implied by '-z'), we promise to output only messages as described in the man page.

Suppress CRLF warnings.
Signed-off-by: Stefan Beller <sbeller@google.com>
---
Maybe something like this?
 builtin/commit.c | 5 +++++
 1 file changed, 5 insertions(+)
diff --git a/builtin/commit.c b/builtin/commit.c
index 00a01f07c3..3705d5ec6f 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -1126,6 +1126,11 @@ static void finalize_deferred_config(struct wt_status *s)
 			die(_("--long and -z are incompatible"));
 	}
 
+	/* suppress all additional output in porcelain mode */
+	if (status_format == STATUS_FORMAT_PORCELAIN ||
+	    status_format == STATUS_FORMAT_PORCELAIN_V2)
+		safe_crlf = SAFE_CRLF_FALSE;
+
 	if (use_deferred_config && status_format == STATUS_FORMAT_UNSPECIFIED)
 		status_format = status_deferred_config.status_format;
 	if (status_format == STATUS_FORMAT_UNSPECIFIED)
-- 
2.13.0.31.g9b732c453e
Torsten Bögershausen· Jul 1, 2017, 12:49 UTC · re: Stefan Beller · lore

Re: [PATCH] status: suppress additional warning output in plumbing modes

 >On 30/06/17 18:28, Stefan Beller wrote:

The patch makes a lot of sense - thanks for the fast reply. A question: does the header correspond to the patch ?

< [PATCH] status: suppress additional warning output in plumbing modes
 > [PATCH] status: suppress CRLF warnings in porcelain modes
(And may be the comment in the code:)
< / * suppress all additional output in porcelain mode */
 > / * suppress CRLF conversion warnings in porcelain mode */
Show 30 quoted lines
> When status is called with '--porcelain' (as implied by '-z'), we promise
> to output only messages as described in the man page.
> 
> Suppress CRLF warnings.
> 
> Signed-off-by: Stefan Beller <sbeller@google.com>
> ---
> 
> Maybe something like this?
> 
>   builtin/commit.c | 5 +++++
>   1 file changed, 5 insertions(+)
> 
> diff --git a/builtin/commit.c b/builtin/commit.c
> index 00a01f07c3..3705d5ec6f 100644
> --- a/builtin/commit.c
> +++ b/builtin/commit.c
> @@ -1126,6 +1126,11 @@ static void finalize_deferred_config(struct wt_status *s)
>   			die(_("--long and -z are incompatible"));
>   	}
>   
> +	/* suppress all additional output in porcelain mode */
> +	if (status_format == STATUS_FORMAT_PORCELAIN ||
> +	    status_format == STATUS_FORMAT_PORCELAIN_V2)
> +		safe_crlf = SAFE_CRLF_FALSE;
> +
>   	if (use_deferred_config && status_format == STATUS_FORMAT_UNSPECIFIED)
>   		status_format = status_deferred_config.status_format;
>   	if (status_format == STATUS_FORMAT_UNSPECIFIED)
> 
Ævar Arnfjörð Bjarmason· Jul 1, 2017, 13:52 UTC · re: Stefan Beller · lore

Re: [PATCH] status: suppress additional warning output in plumbing modes

On Fri, Jun 30 2017, Stefan Beller jotted:
Show 9 quoted lines
> When status is called with '--porcelain' (as implied by '-z'), we promise
> to output only messages as described in the man page.
>
> Suppress CRLF warnings.
>
> Signed-off-by: Stefan Beller <sbeller@google.com>
> ---
>
> Maybe something like this?

It looks sensibly implemented, but as for the approach I think we should just document that you might get errors on stderr, but stable output on stdout.

Many consumers of --porcelain, such as magit, will run arbitrary git output and expect that if they get something on stderr they should be showing it in some special buffer to the user as associated error information.

I think it makes sense to do this & document it in the man page, if you don't care about possible error messages 2>/dev/null is trivial, but it's not trivial to discover in some non-expensive way (parsing the non-porcelain output) that there *are* errors.

Show 19 quoted lines
>  builtin/commit.c | 5 +++++
>  1 file changed, 5 insertions(+)
>
> diff --git a/builtin/commit.c b/builtin/commit.c
> index 00a01f07c3..3705d5ec6f 100644
> --- a/builtin/commit.c
> +++ b/builtin/commit.c
> @@ -1126,6 +1126,11 @@ static void finalize_deferred_config(struct wt_status *s)
>  			die(_("--long and -z are incompatible"));
>  	}
>
> +	/* suppress all additional output in porcelain mode */
> +	if (status_format == STATUS_FORMAT_PORCELAIN ||
> +	    status_format == STATUS_FORMAT_PORCELAIN_V2)
> +		safe_crlf = SAFE_CRLF_FALSE;
> +
>  	if (use_deferred_config && status_format == STATUS_FORMAT_UNSPECIFIED)
>  		status_format = status_deferred_config.status_format;
>  	if (status_format == STATUS_FORMAT_UNSPECIFIED)
Junio C Hamano· Jul 1, 2017, 17:35 UTC · re: Stefan Beller · lore

Re: [PATCH] status: suppress additional warning output in plumbing modes

Stefan Beller <sbeller@google.com> writes:
Show 9 quoted lines
> When status is called with '--porcelain' (as implied by '-z'), we promise
> to output only messages as described in the man page.
>
> Suppress CRLF warnings.
>
> Signed-off-by: Stefan Beller <sbeller@google.com>
> ---
>
> Maybe something like this?

This looks to me like a stimulus having enough time to go to the spinal cord to induce a knee-jerk reaction, without giving a chance to the brain to think things through.

Surely the reported symptom may have only been about CRLF, but who says that would be the only kind of warning that would be seen during "status --porcelain" codepath?

I tend to agree with Ævar's "output for the script can be read from our standard output" should probably be our first response.

The patch _is_ a good start to document that we may want to do something differently under _PORCELAIN output modes and one location in the code that may be a good place to make that decision, but if we are to squelch the warnings, we should make sure we do not give any warning, not limited to squelching the safe-crlf warning, to the standard error, but still diagnose errors and show error messages, or something like that, I would think.

Show 20 quoted lines
>
>  builtin/commit.c | 5 +++++
>  1 file changed, 5 insertions(+)
>
> diff --git a/builtin/commit.c b/builtin/commit.c
> index 00a01f07c3..3705d5ec6f 100644
> --- a/builtin/commit.c
> +++ b/builtin/commit.c
> @@ -1126,6 +1126,11 @@ static void finalize_deferred_config(struct wt_status *s)
>  			die(_("--long and -z are incompatible"));
>  	}
>  
> +	/* suppress all additional output in porcelain mode */
> +	if (status_format == STATUS_FORMAT_PORCELAIN ||
> +	    status_format == STATUS_FORMAT_PORCELAIN_V2)
> +		safe_crlf = SAFE_CRLF_FALSE;
> +
>  	if (use_deferred_config && status_format == STATUS_FORMAT_UNSPECIFIED)
>  		status_format = status_deferred_config.status_format;
>  	if (status_format == STATUS_FORMAT_UNSPECIFIED)
Stefan Beller· Jul 5, 2017, 18:53 UTC · re: Junio C Hamano · lore

Re: [PATCH] status: suppress additional warning output in plumbing modes

On Sat, Jul 1, 2017 at 10:35 AM, Junio C Hamano <gitster@pobox.com> wrote:
Show 16 quoted lines
> Stefan Beller <sbeller@google.com> writes:
>
>> When status is called with '--porcelain' (as implied by '-z'), we promise
>> to output only messages as described in the man page.
>>
>> Suppress CRLF warnings.
>>
>> Signed-off-by: Stefan Beller <sbeller@google.com>
>> ---
>>
>> Maybe something like this?
>
> This looks to me like a stimulus having enough time to go to the
> spinal cord to induce a knee-jerk reaction, without giving a chance
> to the brain to think things through.
>
sort of.
> Surely the reported symptom may have only been about CRLF, but who
> says that would be the only kind of warning that would be seen
> during "status --porcelain" codepath?
I was slightly worried about this, too.
Show 11 quoted lines
>
> I tend to agree with Ævar's "output for the script can be read from
> our standard output" should probably be our first response.
>
> The patch _is_ a good start to document that we may want to do
> something differently under _PORCELAIN output modes and one location
> in the code that may be a good place to make that decision, but if
> we are to squelch the warnings, we should make sure we do not give
> any warning, not limited to squelching the safe-crlf warning, to the
> standard error, but still diagnose errors and show error messages,
> or something like that, I would think.

So for now we'd rather want to go with a documentation patch first and then the refinement of the porcelain mode of potentially suppressing more warnings?

Note that this patch was a one-off by me, so I no longer pursue fixing the problem here, someone else is kindly asked to step up.

Thanks, Stefan

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