diff -u a/libsndfile-1.0.21.ebuild b/libsndfile-1.0.21.ebuild
--- a/libsndfile-1.0.21.ebuild	2010-06-12 12:36:00.000000000 +0000
+++ b/libsndfile-1.0.21.ebuild	2010-08-20 03:53:03.281270523 +0000
@@ -41,6 +41,14 @@
 
 	AT_M4DIR=M4 eautoreconf
 	epunt_cxx
+	INSERT_CHECK='{ const size_t ch_used = strlen(psf->broadcast_var->binfo.coding_history); assert(ch_used < sizeof(psf->broadcast_var->binfo.coding_history)); }'
+	sed -i \
+		-e '19a#include <assert.h>' \
+		-e "87a$INSERT_CHECK" \
+		-e "89a$INSERT_CHECK" \
+		-e "93a$INSERT_CHECK" \
+		-e "96a$INSERT_CHECK" \
+		"${S}"/src/broadcast.c || die "sed failed"
 }
 
 src_compile() {