#178 parsing of pretty=format:"%an %ad" causes fatal: bad revision '%ad'

#178 parsing of pretty=format:"%an %ad" causes fatal: bad revision '%ad'

[Dave Bradley]

Hi,

I’m very new to ‘git’ github. I reported the #178 issue in github and the 
issue has been closed, I believe this means no further discussion.

There are a three additional comments, thank you to the contributors. The 
advise was to discuss upstream which meant nothing to me (again thanks to 
another contributor for clarification).

Summary
------------
The issue reported is (in my opinion) a defect in argument processing 
(happens on Windows and Linux (as per another contributor)).

The issue (in my opinion) is a defect for argument processing by Git. The 
decision (agreement or otherwise) I guess is for this upstream discussion.

I appreciate the open-source git and its usage to the community. But this is 
owned by the discussion group and I doubt my involvement is wanted. So this 
will be my last communication on this issue.

Context
----------
Over many years, I’ve used command-line on Unix/Linux/Windows in both hobby 
and professional modes. In the latter case the processing of arguments with 
spaces has often been the cause of defects (none expected behaviour) for 
newly introduced products.

I’ve found no documentation about the pretty=format behaviour as described 
by the #178 issue. Also, there are many (but incomplete) google-it 
second-hand documents(?) about. So a document fix in the internet age is not 
necessarily the approach to solve an issue, as all those google-it items 
create fog.

For this issue I was processing a git command to run in a GUI and happened 
upon it. The GUI (original design by me) allows interfacing with CVS, SVN, 
HG and maybe now GIT in a similar manner. The GUI holds the interfacing and 
access information and concatenates it onto the VCS command/sub-commands as 
appropriate for a request. Thus, the concatenated VCS request may be 
processed for copy-paste onto a command line window/terminal or (for my GUI) 
executed via a programming language’s command-line-execution class/function 
(Perl, Java, C,.....).

With the argument being further processed within git, it behaves in a manner 
that wasn’t expected.


Thx
Dave

the Issue as reported


Getting a fatal failure when using the following --pretty=format:"%an %ad" 
via a programmed execution from within a programming language. (Java using 
the execution capabilities puts the ' --pretty=format:"%an %ad" ' as an 
argument). This is reproduced on a Windows command-line entry by putting 
double-quotes around the argument. (see below for various examples of pass, 
fail and testing around).

The git argument parser appears to perform a split on spaces within the 
arguments passed to it also. This is not a normal behaviour for any parsing. 
Also, the split is happening within a string quote, it would appear ("%an 
%ad").
Even tried %20 to represent the space.

Thx

G:\ws_test_env\GIT_TESTBED_TMP\fest-swing-1.x>git 
log --all --pretty=format:"%an %ad" -- pom.xml
xxxx xxxx Mon Nov 23 03:09:17 2009 +0000
xxxx xxxx Mon Nov 23 02:42:24 2009 +0000

G:\ws_test_env\GIT_TESTBED_TMP\fest-swing-1.x>git log --all 
"--pretty=format:"%an %ad"" -- pom.xml
fatal: bad revision '%ad'

G:\ws_test_env\GIT_TESTBED_TMP\fest-swing-1.x>git log --all 
"--pretty=format:"%an" "%ad"" -- pom.xml
xxxx xxxx Mon Nov 23 03:09:17 2009 +0000
xxxx xxxx Mon Nov 23 02:42:24 2009 +0000

G:\ws_test_env\GIT_TESTBED_TMP\fest-swing-1.x>git log --all 
"--pretty=format:"%an" " %ad"" -- pom.xml
fatal: bad revision '%ad'

G:\ws_test_env\GIT_TESTBED_TMP\fest-swing-1.x>git log --all 
"--pretty=format:"%an" "%ad"" -- pom.xml
xxxx xxxx Mon Nov 23 03:09:17 2009 +0000
xxxx xxxx Mon Nov 23 02:42:24 2009 +0000

Re: #178 parsing of pretty=format:"%an %ad" causes fatal: bad revision '%ad'

[Erik Faye-Lund]

On Fri, May 2, 2014 at 1:50 PM, Dave Bradley <dbradley2@bell.net> wrote:
> Hi,
>
> I’m very new to ‘git’ github. I reported the #178 issue in github and the
> issue has been closed, I believe this means no further discussion.

When you say "the #178 issue in github", you really mean "issue #178
for Git for Windows on GitHub", available at
https://github.com/msysgit/git/issues/178 for those interested.

That issue tracker is for the Windows port of Git for Windows. It's
intended to track breakages in Git for Windows compared to Git on, say
Linux. It's not a general issue tracker for problems with Git. Still,
it seems a lot of people think "I downloaded Git for Windows, and
here's something that didn't work the way I expected it to, I'll file
a bug". Those kinds of bug-reports usually gets closed quickly, as
it's outside the scope of Git for Windows to decide how Git should
behave - we try to make it behave consistently between Windows and
Unixy-platforms.

This is indeed the right forum to address your issue. So thank you for
moving the discussion here.

Re: #178 parsing of pretty=format:"%an %ad" causes fatal: bad revision '%ad'

[Junio C Hamano]

Erik Faye-Lund <kusmabite@gmail.com> writes:

> On Fri, May 2, 2014 at 1:50 PM, Dave Bradley <dbradley2@bell.net> wrote:
>> Hi,
>>
>> I’m very new to ‘git’ github. I reported the #178 issue in github and the
>> issue has been closed, I believe this means no further discussion.
>
> When you say "the #178 issue in github", you really mean "issue #178
> for Git for Windows on GitHub", available at
> https://github.com/msysgit/git/issues/178 for those interested.
>
> That issue tracker is for the Windows port of Git for Windows. It's
> intended to track breakages in Git for Windows compared to Git on, say
> Linux. It's not a general issue tracker for problems with Git. Still,
> it seems a lot of people think "I downloaded Git for Windows, and
> here's something that didn't work the way I expected it to, I'll file
> a bug". Those kinds of bug-reports usually gets closed quickly, as
> it's outside the scope of Git for Windows to decide how Git should
> behave - we try to make it behave consistently between Windows and
> Unixy-platforms.
>
> This is indeed the right forum to address your issue. So thank you for
> moving the discussion here.

Hmmmmmm, everything you said in the earlier paragraphs is correct,
but I am having a feeling that this is either an issue specific to
the Windows port, or more likely a user error, depending on who is
giving the extra dq quoting.  From the command line:

    $ git show --pretty='format:"%an %ad"'
    "Junio C Hamano Wed Apr 30 11:01:42 2014 -0700"

Because the 'format:' specifier requests to put dq around these two,
we respond by putting dq around these two, just as we were asked to
do.  The way to ask %an followed by SP followed by %ad and nothing
else is

    $ git show --pretty='format:%an %ad'
    Junio C Hamano Wed Apr 30 11:01:42 2014 -0700

Especially this part from the original tells me that this is a user
error and there is nothing wrong in either the generic Git or in the
Windows port.

    G:\w....x>git log --all "--pretty=format:"%an %ad"" -- pom.xml
    fatal: bad revision '%ad'

Separating the tokens on that command line, we would get:

    git
    log
    --all
    --pretty=format:%an
    %ad
    --
    pom.xml

So it told git to run the log subcommand with arguments that tells
it to "include all tips of refs to the starting set", "show them
using a custom format %an", "include %ad to the starting set",
"everything that follows are not revs but pathspecs", and then
finally "pom.xml is the pathspec to limit to paths the user is
interested in".  "%ad is not a rev" is perfectly valid.


You cannot take --pretty=format:"%ad %an" that you see in tutorials
and random web pages too literally.  The double quotes you see in
that example is our way to tell that "--pretty=format:%ad %an" (what
is inside these dq) is expected to be fed to Git as a single
argument.

The examples you see typically follow the convention to show what
you _would_ give to shell to achieve that, and shell's command line
parser needs these dq to make sure that the SP between %an and %ad
is not taken as an argument separator.

Your custom front-end may take a different approach to let you
specify what individual arguments are on your command line, and you
would have to follow its convention.  The user needs to be careful
about how shell quoting works on his/her command line, and that is
all, I would think.

Visiting an earlier part of the original issue report:

    Getting a fatal failure when using the following
    --pretty=format:"%an %ad" via a programmed execution from within
    a programming language. (Java using the execution capabilities
    puts the ' --pretty=format:"%an %ad" ' as an argument).

I take that "Java using ..." to mean that the user wants to see his
machinery eventually do an equivalent to:

	execl('git', 'git', 'log', '--pretty=format:%an %ad', ...);

but it somehow is getting

	execl('git', 'git', 'log', '--pretty=format:%an', '%ad', ...);

due to reason unknown to us that is not in the report.

Without knowing what the end-user input to the front-end that calls
into that "Java" machinery is and what the argument separating
convention that is employed by the front-end is, I cannot tell where
the single argument is split into two.  The problem may either be in
that front-end program and not in the end-user input.  Or the
problem may be in Windows port letting the Windows library split
command line at a funny point.  In any case, it does not sound like
it is a problem in Git.  If the command fed to the equivalent to
execl() above were not 'git' but any program, it will suffer from
the same issue.

Re: #178 parsing of pretty=format:"%an %ad" causes fatal: bad revision '%ad'

[Jonathan Nieder]

Hi Dave,

Dave Bradley wrote:

> G:\ws_test_env\GIT_TESTBED_TMP\fest-swing-1.x>git log --all --pretty=format:"%an %ad" -- pom.xml
> xxxx xxxx Mon Nov 23 03:09:17 2009 +0000
> xxxx xxxx Mon Nov 23 02:42:24 2009 +0000
>
> G:\ws_test_env\GIT_TESTBED_TMP\fest-swing-1.x>git log --all "--pretty=format:"%an %ad"" -- pom.xml
> fatal: bad revision '%ad'

On Linux, this example gets passed to git as six arguments:

	log
	--all
	--pretty=format:%an
	%ad
	--
	pom.xml

I think the intent was instead to pass five arguments (the third being
'--pretty=format:%an %ad').  That means you shouldn't unquote before
the space, or in other words that the space should be part of a quoted
argument.

On Windows, I believe the argument passing convention is more
complicated.  Programs can inspect the entire command line if they
want to.  But there's still an ambiguity in the command you passed: if
I look at space-separated or double-quoted parts of the command line,
it looks like

	git
	log
	--all
	"--pretty=format:"
	(no space)
	%an
	%ad
	(no space)
	""
	--
	pom.xml

What's the right way to parse this?  How can git tell whether %an %ad
were meant to be separate arguments or not?  In absence of a stronger
convention I suspect the simplest rule is to mimic what a Unix shell
does, where they are separate arguments because the space is not
quoted.

Cc-ing Windows folks in case they have more insight.

Thanks and hope that helps,
Jonathan

Re: #178 parsing of pretty=format:"%an %ad" causes fatal: bad revision '%ad'

[Jonathan Nieder]

(resending with the correct address for the Git for Windows developers.
Sorry for the noise.)
Hi Dave,

Dave Bradley wrote:

> G:\ws_test_env\GIT_TESTBED_TMP\fest-swing-1.x>git log --all --pretty=format:"%an %ad" -- pom.xml
> xxxx xxxx Mon Nov 23 03:09:17 2009 +0000
> xxxx xxxx Mon Nov 23 02:42:24 2009 +0000
>
> G:\ws_test_env\GIT_TESTBED_TMP\fest-swing-1.x>git log --all "--pretty=format:"%an %ad"" -- pom.xml
> fatal: bad revision '%ad'

On Linux, this example gets passed to git as six arguments:

	log
	--all
	--pretty=format:%an
	%ad
	--
	pom.xml

I think the intent was instead to pass five arguments (the third being
'--pretty=format:%an %ad').  That means you shouldn't unquote before
the space, or in other words that the space should be part of a quoted
argument.

On Windows, I believe the argument passing convention is more
complicated.  Programs can inspect the entire command line if they
want to.  But there's still an ambiguity in the command you passed: if
I look at space-separated or double-quoted parts of the command line,
it looks like

	git
	log
	--all
	"--pretty=format:"
	(no space)
	%an
	%ad
	(no space)
	""
	--
	pom.xml

What's the right way to parse this?  How can git tell whether %an %ad
were meant to be separate arguments or not?  In absence of a stronger
convention I suspect the simplest rule is to mimic what a Unix shell
does, where they are separate arguments because the space is not
quoted.

Cc-ing Windows folks in case they have more insight.

Thanks and hope that helps,
Jonathan

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Re: Re: #178 parsing of pretty=format:"%an %ad" causes fatal: bad revision '%ad'

[Erik Faye-Lund]

On Fri, May 2, 2014 at 7:23 PM, Jonathan Nieder <jrnieder@gmail.com> wrote:
> (resending with the correct address for the Git for Windows developers.
> Sorry for the noise.)
> Hi Dave,
>
> Dave Bradley wrote:
>
>> G:\ws_test_env\GIT_TESTBED_TMP\fest-swing-1.x>git log --all --pretty=format:"%an %ad" -- pom.xml
>> xxxx xxxx Mon Nov 23 03:09:17 2009 +0000
>> xxxx xxxx Mon Nov 23 02:42:24 2009 +0000
>>
>> G:\ws_test_env\GIT_TESTBED_TMP\fest-swing-1.x>git log --all "--pretty=format:"%an %ad"" -- pom.xml
>> fatal: bad revision '%ad'
>
> On Linux, this example gets passed to git as six arguments:
>
>         log
>         --all
>         --pretty=format:%an
>         %ad
>         --
>         pom.xml
>

As does it on Windows.

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*** (do not pretend to know who is subscribed and who is not) ***
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Re: [msysGit] Re: #178 parsing of pretty=format:"%an %ad" causes fatal: bad revision '%ad'

[Dave Bradley]

Hi,

Interesting discussion. However, the example below of three-spaces between 
"%an"  and "%ad" in the example below resulted in the
formatting of the output with the three spaces,  but no dq's.

> Original #178 content
>G:\ws_test_env\GIT_TESTBED_TMP\fest-swing-1.x>git log --all 
>"--pretty=format:"%an"    "%ad"" -- pom.xml
>xxxx xxxx    Mon Nov 23 03:09:17 2009 +0000
>xxxx xxxx    Mon Nov 23 02:42:24 2009 +0000

This added to my confusion as by right dq within dq should be formatted. 
(Yea right, these days its needs to be escaped. But haven't tried that.)

In summary so far, it would appear that the --pretty......... needs to be 
contained in double-quotes as a whole. This was the solution I applied to my 
problem.

In the discussions I've seen more information requested as to the arguments 
provided to the execution class. I solved this issue as I made it work by 
experiment. I format the argument as a whole and don't have the space. IE. 
"pretty=format:"name:%an%nauthor:%ad%n"".


Regards

-----Original Message----- 
From: Erik Faye-Lund
Sent: Friday, May 02, 2014 2:23 PM
To: Jonathan Nieder
Cc: Dave Bradley ; GIT Mailing-list ; msysGit
Subject: Re: [msysGit] Re: #178 parsing of pretty=format:"%an %ad" causes 
fatal: bad revision '%ad'

On Fri, May 2, 2014 at 7:23 PM, Jonathan Nieder <jrnieder@gmail.com> wrote:
> (resending with the correct address for the Git for Windows developers.
> Sorry for the noise.)
> Hi Dave,
>
> Dave Bradley wrote:
>
>> G:\ws_test_env\GIT_TESTBED_TMP\fest-swing-1.x>git 
>> log --all --pretty=format:"%an %ad" -- pom.xml
>> xxxx xxxx Mon Nov 23 03:09:17 2009 +0000
>> xxxx xxxx Mon Nov 23 02:42:24 2009 +0000
>>
>> G:\ws_test_env\GIT_TESTBED_TMP\fest-swing-1.x>git log --all 
>> "--pretty=format:"%an %ad"" -- pom.xml
>> fatal: bad revision '%ad'
>
> On Linux, this example gets passed to git as six arguments:
>
>         log
>         --all
>         --pretty=format:%an
>         %ad
>         --
>         pom.xml
>

As does it on Windows. 

Re: [msysGit] Re: #178 parsing of pretty=format:"%an %ad" causes fatal: bad revision '%ad'

[Junio C Hamano]

Dave Bradley <dbradley2@bell.net> writes:

>> Original #178 content
>> G:\ws_test_env\GIT_TESTBED_TMP\fest-swing-1.x>git log --all
>> "--pretty=format:"%an"    "%ad"" -- pom.xml
>>xxxx xxxx    Mon Nov 23 03:09:17 2009 +0000
>>xxxx xxxx    Mon Nov 23 02:42:24 2009 +0000
>
> This added to my confusion as by right dq within dq should be
> formatted.

I do not see any dq within dq here.  Perhaps you need to count again
to see which one pairs with which one.

What I see are these three strings concatenated together:

        --pretty=format: (which does not need any dq)
        %an"   "%ad     (the dq protects 3 SPs inside)
                        (an empty string inside the final dq pair)

So the single parameter that begins with --pretty given to "git log"
is exactly the same as what is inside the single dq pair in the
following:

	"--pretty=format:%an   %ad"

A more conventional way to spell it may however be one of:

	--pretty=format:"%an   %ad"
	--pretty="format:%an   %ad"