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

From: Jonathan Nieder <[email-masked]>
Date: Fri, 2 May 2014 10:22:56 -0700

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