Negative line number reported in output messages

[maverickwoo]

I am using 652176e with asciidoctor bd8927b (both latest as of this writing).

First, create two files:

1. foo.adoc

   
   = Negative line number

include::bar.adoc[]

2. `bar.adoc`

== A

==== B

b

==== C

c

Then run `asciidoctor-latex foo.adoc`. The output says:

asciidoctor: WARNING: foo.adoc: line -3: section title out of sequence: expected level 2, got level 3 asciidoctor: WARNING: foo.adoc: line 1: section title out of sequence: expected level 2, got level 3