Re: [PATCH] tools/pygrub: do not override pygrub with a symbolic link

[Christoph Egger <chegger@amazon.de>]

On 22.04.13 13:58, Ian Campbell wrote:
> On Mon, 2013-04-22 at 12:50 +0100, Christoph Egger wrote:
>> tools/pygrub: Do not override pygrub with a symbolic link if $(BINDIR)
>> and $(PRIVATE_BINDIR) are the same.
> 
> More properly this is "fix the if condition we use to decide when to
> create the symlink", since it is already the intention to not override
> if they are the same  but the condition is written wrong since it
> includes DESTDIR on one side but not the other, which defeats the check.
> 
> FWIW I would niuke the DESTDIR on the left rather than adding it on the
> right, it might even fit on one line then?

Does not work. See comment below.

> 
>> Signed-off-by: Christoph Egger <chegger@amazon.de>
>> diff --git a/tools/pygrub/Makefile b/tools/pygrub/Makefile
>> index 039f7f7..c3b34d7 100644
>> --- a/tools/pygrub/Makefile
>> +++ b/tools/pygrub/Makefile
>> @@ -15,8 +15,8 @@ install: all
>>  		--install-scripts=$(PRIVATE_BINDIR) --force
>>  	$(INSTALL_DIR) $(DESTDIR)/var/run/xend/boot
>>  	set -e; if [ "`readlink -f $(DESTDIR)/$(BINDIR)`" != \
>> -	             "`readlink -f $(PRIVATE_BINDIR)`" ]; then \
>> -	    ln -sf $(PRIVATE_BINDIR)/pygrub $(DESTDIR)/$(BINDIR); \
>> +	             "`readlink -f $(DESTDIR)/$(PRIVATE_BINDIR)`" ]; then \
>> +	    ln -sf $(DESTDIR)/$(PRIVATE_BINDIR)/pygrub $(DESTDIR)/$(BINDIR); \
> 
> I don't think this change to the first path passed to ln is correct
> since this will become the content of the symlink, which doesn't want to
> include DESTDIR.

What actually happens when $(BINDIR) and $(PRIVATE_BINDIR) are equal
is that the pygrub python script does not exist. pygrub is a symbolic
link to a file that doesn't exist instead.

With this patch you will actually install the pygrub python script
rather a symbolic link.

Christoph