further tweak SvPV() docs

Make it clear that a different pointer may be returned each time.

1 files changed, 7 insertions, 5 deletions

diff --git a/sv.h b/sv.h
index 4bfbf9c041..7baef34c56 100644
--- a/sv.h
+++ b/sv.h
@@ -1490,11 +1490,13 @@ stringified version becoming C<SvPOK>.  Handles 'get' magic.  See also
 C<SvPVx> for a version which guarantees to evaluate sv only once.
 
 Note that there is no guarantee that the return value of C<SvPV()> is
-equal to C<SvPVX(sv)> (or even that C<SvPVX(sv)> contains valid data), due
-to the way that things like overloading and Copy-On-Write are handled.  In
-these cases, the return value may point to a temporary buffer or similar.
-If you absolutely need the SvPVX field to be valid (for example, if you
-intend to write to it), then see L</SvPV_force>.
+equal to C<SvPVX(sv)>, or that C<SvPVX(sv)> contains valid data, or that
+successive calls to C<SvPV(sv)) will return the same pointer value each
+time. This is due to the way that things like overloading and
+Copy-On-Write are handled.  In these cases, the return value may point to
+a temporary buffer or similar.  If you absolutely need the SvPVX field to
+be valid (for example, if you intend to write to it), then see
+L</SvPV_force>.
 
 =for apidoc Am|char*|SvPVx|SV* sv|STRLEN len
 A version of C<SvPV> which guarantees to evaluate C<sv> only once.