AddressSanitizer reports a heap buffer overflow from skip_node_separator() on malformed info file

[Nathaniel Beaver]

Steps to reproduce:
Compile with -fsanitize=address, then run:

info -f reproduce_bug.info

Expected behavior:

info does not trigger AddressSanitizer errors.

Actual behavior:

AddressSanitizer reports a heap-buffer-overflow from 
skip_node_separator() in info/search.c:645

Comments:
This file was generated by afl-fuzz and then hand-edited; I don't 
understand how it creates a heap buffer overflow.

Sincerely,

Nathaniel Beaver

P.S. Version information:

$ git describe --tags
texinfo-6.6-794-ga11612ff66
$ git rev-parse HEAD
a11612ff665391142fc8adb90796741cabb3b683
$ info/ginfo --version | head -n 1
info (GNU texinfo) 6.7.90

address-sanitizer.txt
Description: Text document

original.info
Description: application/info

reproduce_bug.info
Description: application/info