handling mount points in grub-mkrelpath

[Felix Zielcke <fzielcke@z-51.de>]

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Vladimir wanted to have this discussed on ML

The old shell function make_system_path_relative_to_its_root outputed /
if you gave it /boot and it was on a seperate partition.
grub-mkrelpath currently outputs /boot

This breaks booting at least with the 10_linux generated entries.

Attached is my fix for that, which I'll update today to Debian.

We already broke backward compatibility with the commandline for Xen.
IMO in this grub-mkrelpath case there's no need to break compatibility.

But maybe I can find a good way to handle this inside
util/grub-mkconfig_lib.in just for compatibility.
-- 
Felix Zielcke
Proud Debian Maintainer and GNU GRUB developer

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2009-11-29 Felix Zielcke <fzielcke@z-51.de>

	* util/misc.c (make_system_path_relative_to_its_root): Correctly cope with
	mount points.
=== modified file 'util/misc.c'
--- util/misc.c	2009-11-25 23:10:02 +0000
+++ util/misc.c	2009-11-29 19:19:28 +0000
@@ -500,7 +500,17 @@ make_system_path_relative_to_its_root (c
 
       /* buf is another filesystem; we found it.  */
       if (st.st_dev != num)
-	break;
+	{
+	  /* offset == 0 means path given is the mount point.  */
+	  if (offset == 0)
+	    {
+	      free (buf);
+	      free (buf2);
+	      return strdup ("/");
+	    }
+	  else
+	    break;
+	}
 
       offset = p - buf;
       /* offset == 1 means root directory.  */