S_hv_delete_common(): avoid undefined behaviour

ASAN -fsanitize-undefined was tripping on the second of these two lines:

    svp = AvARRAY(isa);
    end = svp + AvFILLp(isa)+1;

In the case where svp is NULL and AvFILLp(isa) is -1, the first addition
is undefined behaviour. Add the 1 first, so that it becomes
svp + (-1+1), which is safe.

1 files changed, 1 insertions, 1 deletions

diff --git a/hv.c b/hv.c
index d3d02d1046..fc90a5146b 100644
--- a/hv.c
+++ b/hv.c
@@ -1295,7 +1295,7 @@ S_hv_delete_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
                             SV **svp, **end;
                         strip_magic:
                             svp = AvARRAY(isa);
-                            end = svp + AvFILLp(isa)+1;
+                            end = svp + (AvFILLp(isa)+1);
                             while (svp < end) {
                                 if (*svp)
                                     mg_free_type(*svp, PERL_MAGIC_isaelem);