Re: gzip --force bug

[Jim Meyering]

Mark Adler wrote:
> Jim,
>
> Below is a patch to the patch.
>
> A test case will be forthcoming (I need to create a case that delicately 
> crosses a buffer boundary).  Once I get a test case working, you can push it.
>
> By the way, I found an even more serious incarnation of the original bug 
> shown by this test case:
>
> $ echo -n x | gzip124 -cdf | wc -c
>        0
> $ echo -n x | gzip14 -cdf | wc -c
>        0
>
> It should be the same as cat:
>
> $ echo -n x | cat | wc -c
>        1
> $ echo -n x | ./gzip -cdf | wc -c
>        1
>
> Test cases to add for completeness are:
>
> $ echo -n | ./gzip -cdf | wc -c
> $ echo -n x | ./gzip -cdf | wc -c
> $ echo -n xy | ./gzip -cdf | wc -c
> $ echo -n xyz | ./gzip -cdf | wc -c
>
> Those should return 0, 1, 2, and 3 respectively.

Thanks.
I've added the following test.
It tests for preserved content, too.

>From 9ff85940c4e7c35739ffda73129bfe8ab34bbc8f Mon Sep 17 00:00:00 2001
From: Jim Meyering <address@hidden>
Date: Thu, 4 Feb 2010 08:09:23 +0100
Subject: [PATCH] tests: add more tests of gzip -cdf

* tests/mixed: Test "gzip -cdf" for a range of small uncompressed files.
---
 tests/mixed |   21 +++++++++++++++++++++
 1 files changed, 21 insertions(+), 0 deletions(-)

diff --git a/tests/mixed b/tests/mixed
index 903a644..65898a1 100644
--- a/tests/mixed
+++ b/tests/mixed
@@ -50,4 +50,25 @@ compare out exp2 || fail=1
 gzip -cdf < in > out || fail=1
 compare out exp2 || fail=1

+in_str=0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ_-+=%
+for i in 0 1 2 3 4 5 6 7 8 9 a; do in_str="$in_str$in_str" ;done
+
+# Start with some small sizes.  $(seq 64)
+sizes=$(i=0; while :; do echo $i; test $i = 64; i=$(expr $i + 1) && break; 
done)
+
+# gzip's internal buffer size is 32KiB + 64 bytes:
+sizes="$sizes 32831 32832 32833"
+
+# 128KiB, +/- 1
+sizes="$sizes 131071 131072 131073"
+
+# Ensure that "gzip -cdf" acts like cat, for a range of small input files.
+i=0
+for i in $sizes; do
+  echo $i
+  printf %$i.${i}s $in_str > in
+  gzip -cdf < in > out
+  compare in out || fail=1
+done
+
 Exit $fail
--
1.7.0.rc1.193.ge8618