With the following configuration:

magic_quotes_sybase = on
magic_quotes_gpc    = on 

Currently (as of php4.3.0-dev) the following behavior exists:

a) Makes GPC foo's into foo''s (as advertised)
b) Doesn't touch foo"s, foo"s remains foo"s.  The same can be said for \ and NUL's as they are unaffected by magic_quotes_gpc when _sybase is On!

In summary, _sybase takes over _gpc and only ' are escaped.  The rest remain untouched as if _gpc is off.  This behavior is unexpected to me as I would still expect magic_quotes_gpc to affect ", \ and NUL's.  get_magic_quotes_gpc() still returns true even when ", \ and NUL's are not escaped, this seems odd.  I haven't seen one quotes management solution out there in phpland that takes into account _sybase so am a little worried.

Proposal:

If both _gpc and _sybase are On:

a) foo's turns to foo''s as advertised (like current)
b) magic_quotes_gpc will still affect everything else except single quotes, with backslashes.

Regarding BC. I'm not sure if this change will affect BC nor am I all that familiar with Sybase or character escaping in general so please comment.  I vote the above proposal is discussed and if approved implemented into PHP 4.3.0