[Bug libbacktrace/103167] UBSAN error since g:05f40bc4c116ba48843728201bc7290a5e518598

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103167

--- Comment #5 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Martin Liška from comment #1)
> /home/mliska/Programming/binutils-gdb/libbacktrace/xztest.c:175:13: runtime
> error: null pointer passed as argument 2, which is declared to never be null

diff --git a/libbacktrace/xztest.c b/libbacktrace/xztest.c
index b2533cb1804..a42bc59efd8 100644
--- a/libbacktrace/xztest.c
+++ b/libbacktrace/xztest.c
@@ -172,7 +172,7 @@ test_samples (struct backtrace_state *state)
                       tests[i].name, uncompressed_len, v);
              ++failures;
            }
-         else if (memcmp (tests[i].uncompressed, uncompressed, v) != 0)
+         else if (v && memcmp (tests[i].uncompressed, uncompressed, v) != 0)
            {
              size_t j;