On 5/8/23 03:16, Tom Lane wrote:
> I wrote:
>> Michael Paquier <mich...@paquier.xyz> writes:
>>> While testing this patch, I have triggered an error pointing out that
>>> the decompression path of LZ4 is broken for table data. I can
>>> reproduce that with a dump of the regression database, as of:
>>> make installcheck
>>> pg_dump --format=d --file=dump_lz4 --compress=lz4 regression
>
>> Ugh. Reproduced here ... so we need an open item for this.
>
> BTW, it seems to work with --format=c.
>
The LZ4Stream_write() forgot to move the pointer to the next chunk, so
it was happily decompressing the initial chunk over and over. A bit
embarrassing oversight :-(
The custom format calls WriteDataToArchiveLZ4(), which was correct.
The attached patch fixes this for me.
regards
--
Tomas Vondra
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company
diff --git a/src/bin/pg_dump/compress_lz4.c b/src/bin/pg_dump/compress_lz4.c
index 423e1b7976f..43c4b9187ef 100644
--- a/src/bin/pg_dump/compress_lz4.c
+++ b/src/bin/pg_dump/compress_lz4.c
@@ -584,6 +584,8 @@ LZ4Stream_write(const void *ptr, size_t size, CompressFileHandle *CFH)
errno = (errno) ? errno : ENOSPC;
return false;
}
+
+ ptr = ((char *) ptr) + chunk;
}
return true;
