liblzma: Make Valgrind happier with optimized (gcc -O2) liblzma.
When optimizing, GCC can reorder code so that an uninitialized
value gets used in a comparison, which makes Valgrind unhappy.
It doesn't happen when compiled with -O0, which I tend to use
when running Valgrind.
Thanks to Rich Prohaska. I remember this being mentioned long
ago by someone else but nothing was done back then.
diff --git a/src/liblzma/lz/lz_encoder.c b/src/liblzma/lz/lz_encoder.c
index 48bc487..5a2be79 100644
--- a/src/liblzma/lz/lz_encoder.c
+++ b/src/liblzma/lz/lz_encoder.c
@@ -541,7 +541,11 @@
next->coder->lz.code = NULL;
next->coder->lz.end = NULL;
+ // mf.size is initialized to silence Valgrind
+ // when used on optimized binaries (GCC may reorder
+ // code in a way that Valgrind gets unhappy).
next->coder->mf.buffer = NULL;
+ next->coder->mf.size = 0;
next->coder->mf.hash = NULL;
next->coder->mf.son = NULL;
next->coder->mf.hash_count = 0;
