Tighten the vec() code so that naughty BITS cause an error.

[p5sagit/p5-mst-13.2.git] / doop.c

diff --git a/doop.c b/doop.c
index b064838..36fb6b3 100644 (file)
--- a/doop.c
+++ b/doop.c
@@ -704,8 +704,10 @@ Perl_do_vecget(pTHX_ SV *sv, I32 offset, I32 size)
     unsigned char *s = (unsigned char *) SvPV(sv, srclen);
     UV retnum = 0;
 
-    if (offset < 0 || size < 1)
+    if (offset < 0)
        return retnum;
+    if (size < 1 || (size & (size-1))) /* size < 1 or not a power of two */ 
+       Perl_croak(aTHX_ "Illegal number of bits in vec");
     offset *= size;    /* turn into bit offset */
     len = (offset + size + 7) / 8;     /* required number of bytes */
     if (len > srclen) {
@@ -735,8 +737,6 @@ Perl_do_vecget(pTHX_ SV *sv, I32 offset, I32 size)
                        ((UV) s[offset + 1] << 16) +
                        (     s[offset + 2] <<  8);
            }
-           else
-               Perl_croak(aTHX_ "Illegal number of bits in vec");
        }
     }
     else if (size < 8)
@@ -755,8 +755,6 @@ Perl_do_vecget(pTHX_ SV *sv, I32 offset, I32 size)
                ((UV) s[offset + 1] << 16) +
                (     s[offset + 2] <<  8) +
                      s[offset + 3];
-       else
-           Perl_croak(aTHX_ "Illegal number of bits in vec");
     }
 
     return retnum;
@@ -780,6 +778,8 @@ Perl_do_vecset(pTHX_ SV *sv)
     lval = SvUV(sv);
     offset = LvTARGOFF(sv);
     size = LvTARGLEN(sv);
+    if (size < 1 || (size & (size-1))) /* size < 1 or not a power of two */ 
+       Perl_croak(aTHX_ "Illegal number of bits in vec");
     
     offset *= size;                    /* turn into bit offset */
     len = (offset + size + 7) / 8;     /* required number of bytes */