make SvUPGRADE() a statement.

To guote the perldelta entry:

SvUPGRADE() is no longer an expression. Originally this macro (and its
underlying function, sv_upgrade()) were documented as boolean, although
in reality they always croaked on error and never returned false. In 2005
the documentation was updated to specify a void return value, but
SvUPGRADE() was left always returning 1 for backwards compatibility. This
has now been removed, and SvUPGRADE() is now a statement with no return
value.

So this is now a syntax error:

    if (!SvUPGRADE(sv)) { croak(...); }

If you have code like that, simply replace it with

    SvUPGRADE(sv);

1 files changed, 2 insertions, 1 deletions

diff --git a/sv.h b/sv.h
index e3c26731fe..c017454c44 100644
--- a/sv.h
+++ b/sv.h
@@ -327,7 +327,8 @@ perform the upgrade if necessary.  See C<svtype>.
    them all by using a consistent macro.  */
 #define SvIS_FREED(sv)	((sv)->sv_flags == SVTYPEMASK)
 
-#define SvUPGRADE(sv, mt) (SvTYPE(sv) >= (mt) || (sv_upgrade(sv, mt), 1))
+#define SvUPGRADE(sv, mt) \
+        STMT_START { if (SvTYPE(sv) < (mt)) sv_upgrade(sv, mt); } STMT_END
 
 #define SVf_IOK		0x00000100  /* has valid public integer value */
 #define SVf_NOK		0x00000200  /* has valid public numeric value */