barebox-state (dt-utils): dump-shell broken for state at 0

[Sascha Hauer]

+Cc mkl who wrote 6d58ca4

On Mon, Apr 04, 2016 at 11:44:51PM +0200, Andreas Pretzsch wrote:
> On Mi, 2015-06-17 at 11:06 +0200, Sascha Hauer wrote:
> > On Wed, Jun 17, 2015 at 08:42:50AM +0200, Jan Remmet wrote:
> > > Hello,
> > > I'm working with barebox states and wonder if there is already a tool to access
> > > states in eeprom from linux?
> > > The states from a dtb backend should be easy to read. For raw there must be
> > > looked under /proc/devicetree or a state kernel driver.
> > 
> > Yes, there is such a tool here:
> > 
> > git://git.pengutronix.de/git/tools/dt-utils.git
> > 
> > The binary you'll need is barebox-state.
> 
> barebox-state provides a command "--dump-shell" to dump the state
> suitable for shell sourcing.
> Essentially, it prints out variable=value pairs.
> So typical use would be a
> 	eval `barebox-state --dump-shell`
> somewhere in a shell script (incl. simple ones like busybox ash).
> 
> Unfortunately, this breaks with indices in the state name, as @ is not
> escaped.
> Tested with dt-utils v2015.10.0, but according to code this is the case
> from v2015.05.0 up until master.
> 
> As of commit 6d58ca4 "barebox-state: fix export of shell variables:",
> the fixed prefix "STATE_" was replaced by the supplied state name.
> Also in there, all '.' are replaced by '_' in the variable name. Not in
> the state name itself.
> 
> The same would be necessary for (at least) '@', because it is invalid
> also inside a shell variable name. As probably other chars, just I'm not
> sure which might show up from the dts. So no premature patch from my
> side.
> Not only for the variable name, but also the state name itself.
> 
> For clarification of the setup and behaviour, see below.
> 
> 
> Now, question would be how to fix this.
> Also replacing '@' by '_' might break existing users (e.g. when parsing
> from stdin or similar, instead of using shells eval command).
> On the other hand, status quo breaks the "described" use of dump
> _shell_ ...
> 
> Talking about this, it might be also some idea to resurrect the old
> behaviour of always printing 'STATE_' as prefix instead of the state
> name from dts. Not sure if it's the best idea, or how to call such an
> extra option, didn't think it through by now.
> Just saying, as I will go this way here (as a hotfix) for my setup...
> 
> Ideas, opinions ?

I'm in favor for resurrecting the old 'STATE_' behaviour, but I don't
know why Marc changed it. Maybe he has some more input.

Sascha

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