[OpenBIOS] next-property

[Olivier Danet]

I may have found a bug in OpenBIOS.

An OS uses the "nextprop" iterator to scan device properties, and eventually
   asks about nonexistant properties.
"const char *obp_nextprop(int node, const char *name)" 
(arch/sparc32/romvec.c)
   calls the "next-property" forth code, then pops the result.
According to the standard, next-property should return 0 if the property 
selected
   is the last _OR_ if the property does not exist.
The current code in forth/admin/devices.fs returns nothing when the 
property does
   not exit.

For example (SPARC 32) :

cd screen
" name" ?active-package next-property drop cr type
  --> returns "device_type"

" interrupts" ?active-package next-property
  --> returns 0, this is the last property.

" bozo" ?active-package next-property
  --> returns nothing. Which, imho, is wrong.

Here is a patch, I am not quite sure about it (debuting Forth)
   but it helps the target OS :

Index: forth/device/property.fs
===================================================================
--- forth/device/property.fs    (révision 1246)
+++ forth/device/property.fs    (copie de travail)
@@ -70,7 +70,7 @@
      2drop r> >dn.properties @
    else
      r> find-property dup if @ then
-    ?dup if >prop.next @ then
+    dup if >prop.next @ then
    then

    ?dup if
===================================================================

The standard asks for a pointer to a zero lenght string instead of zero,
   the C code obp_nextprop() expects a zero. I don't know if it makes a
   difference.

Olivier
(Btw, the OS is NetBSD :-)