Changed parser semantics around skipping.

Prior to this change:

  parse(buf, len) -> len + N

...would indicate that the next N bytes of the input are not
needed, *and* would advance the decoding position by this
much.

After this change:

  parse(buf, len) -> len + N
  parse(NULL, N) -> N

...can be used to achieve the same thing.  But skipping the
N bytes is not explicitly performed by the user.  A user that
doesn't want/need to skip can just say:

  parsed = parse(buf, len);

  if (parsed < len) {
    // Handle suspend, advance stream by "parsed".
  } else {
    // Stream was advanced by "len" (even if parsed > len).
  }

Updated unit tests to test this new behavior, and refactored
test utility code a bit to support it.

1 files changed, 1 insertions, 1 deletions

diff --git a/upb/sink.h b/upb/sink.h
index e7d4960..765916e 100644
--- a/upb/sink.h
+++ b/upb/sink.h
@@ -272,7 +272,7 @@ UPB_INLINE bool upb_bufsrc_putbuf(const char *buf, size_t len,
   upb_bufhandle_setbuf(&handle, buf, 0);
   ret = upb_bytessink_start(sink, len, &subc);
   if (ret && len != 0) {
-    ret = (upb_bytessink_putbuf(sink, subc, buf, len, &handle) == len);
+    ret = (upb_bytessink_putbuf(sink, subc, buf, len, &handle) >= len);
   }
   if (ret) {
     ret = upb_bytessink_end(sink);