Re: bin/57525: file: lhs/off overflow on gzipped file

[mlelstv%serpens.de@localhost (Michael van Elst)]

The following reply was made to PR bin/57525; it has been noted by GNATS.

From: mlelstv%serpens.de@localhost (Michael van Elst)
To: gnats-bugs%netbsd.org@localhost
Cc: 
Subject: Re: bin/57525: file: lhs/off overflow on gzipped file
Date: Thu, 13 Jul 2023 15:51:28 -0000 (UTC)

 roland.illig%gmx.de@localhost writes:
 
 >$ touch -t 202307131323 f
 >$ gzip -c f | file -
 >lhs/off overflow 4206102536 0
 >/dev/stdin: gzip compressed data, was "f", last modified: Thu Jul 13 13:23:00 2023, from Unix
 
 
 That error message should better be left for debugging.
 
 file(1) checks for:
 
 (0x02.l)        string  *IDENTIFICATION         Becker & Hickl PMS Data File
 
 the little-endian signed 32bit value at offset 2 is interpreted as an
 offset into the file where the string "*IDENTIFICATION" acts as a magic
 number.
 
 The error message is about the parsed offset being out of range for a
 signed value (the value is printed then as unsigned). The message is
 fine, if the offset were used to fetch additional data from a file,
 but not useful, when identifying the file format.
 
 N.B. I have no idea why the file format defines the offset to be
 interpreted as a signed value. But that's not the problem of file(1).