1 files changed, 4 insertions, 1 deletions
diff --git a/upb/bytestream.c b/upb/bytestream.c
index 4f6e4b1..812e552 100644
--- a/upb/bytestream.c
+++ b/upb/bytestream.c
@@ -32,6 +32,8 @@ upb_byteregion *upb_byteregion_newl(const void *str, size_t len) {
   memcpy(ptr, str, len);
   ptr[len] = '\0';
   upb_stringsrc_reset(src, ptr, len);
+  upb_byteregion_fetch(upb_stringsrc_allbytes(src));
+  assert(len == upb_byteregion_available(upb_stringsrc_allbytes(src), 0));
   return upb_stringsrc_allbytes(src);
 }
 
@@ -241,9 +243,10 @@ upb_bytesink* upb_stdio_bytesink(upb_stdio *stdio) { return &stdio->sink; }
 
 upb_bytesuccess_t upb_stringsrc_fetch(void *_src, uint64_t ofs, size_t *read) {
   upb_stringsrc *src = _src;
-  assert(ofs < src->len);
+  assert(ofs <= src->len);
   if (ofs == src->len) {
     upb_status_seteof(&src->bytesrc.status);
+    *read = 0;
     return UPB_BYTE_EOF;
   }
   *read = src->len - ofs;