DOC: fix typo in the body parser documentation for msg.sov
"positive" ... "null or positive". The second one is "null or negative".
diff --git a/doc/internals/body-parsing.txt b/doc/internals/body-parsing.txt
index 5baa549..f585c1e 100644
--- a/doc/internals/body-parsing.txt
+++ b/doc/internals/body-parsing.txt
@@ -69,7 +69,7 @@
msg.sov : start of value. First character of the header's value in the header
states, start of the body in the data states. Strictly positive
values indicate that headers were not forwarded yet (<buf.p> is
- before the start of the body), and null or positive values are seen
+ before the start of the body), and null or negative values are seen
after headers are forwarded (<buf.p> is at or past the start of the
body). The value stops changing when data start to leave the buffer
(in order to avoid integer overflows). So the maximum possible range