diff options
| author | Tom Lane <tgl@sss.pgh.pa.us> | 2025-10-13 12:44:20 -0400 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2025-10-13 12:44:20 -0400 |
| commit | a239c4a0c22627a45c0a91d2f4d9755bbc5be7be (patch) | |
| tree | 5a394462f6526e2429039740ce78d5f7e97fc5c6 | |
| parent | d3ba50db48e66be8804b9edf093b0f921d625425 (diff) | |
Fix issue with reading zero bytes in Gzip_read.
pg_dump expects a read request of zero bytes to be a no-op; see for
example ReadStr(). Gzip_read got this wrong and falsely supposed
that the resulting gzret == 0 indicated an error. We could complicate
that error-checking logic some more, but it seems best to just fall
out immediately when passed size == 0.
This bug breaks the nominally-supported case of manually gzip'ing
the toc.dat file within a directory-style dump, so back-patch to v16
where this code came in. (Prior branches already have a short-circuit
for size == 0 before their only gzread call.)
Author: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Discussion: https://postgr.es/m/3515357.1760128017@sss.pgh.pa.us
Backpatch-through: 16
| -rw-r--r-- | src/bin/pg_dump/compress_gzip.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/src/bin/pg_dump/compress_gzip.c b/src/bin/pg_dump/compress_gzip.c index 4a067e1402c..ad3b6486027 100644 --- a/src/bin/pg_dump/compress_gzip.c +++ b/src/bin/pg_dump/compress_gzip.c @@ -257,6 +257,10 @@ Gzip_read(void *ptr, size_t size, CompressFileHandle *CFH) gzFile gzfp = (gzFile) CFH->private_data; int gzret; + /* Reading zero bytes must be a no-op */ + if (size == 0) + return 0; + gzret = gzread(gzfp, ptr, size); /* |