RSTRING_PTR and RSTRING_LEN fixes for Ruby 1.8.5 compatibility (wikitext, 7e157f8)

Created 2/29/2008, updated 3/5/2024

snippets

Testing on RHEL 5.1, which comes with Ruby 1.8.5, indicates that 1.8.5 doesn't define the RSTRING_PTR and RSTRING_LEN macros, so define them if they're not already defined.

Signed-off-by: Greg Hurrell <greg@hurrell.net>