Don't call fwrite() with len == 0 when writing out relcache init file.

Noticed via -fsanitize=undefined.

Backpatch to all branches, for the same reasons as 46ab07ffda.

Discussion: https://postgr.es/m/20220323173537.ll7klrglnp4gn2um@alap3.anarazel.de
Backpatch: 10-
This commit is contained in:
Andres Freund 2022-03-23 13:05:25 -07:00
parent e71c76fcab
commit 1c6bb380e5
1 changed files with 1 additions and 1 deletions

View File

@ -6528,7 +6528,7 @@ write_item(const void *data, Size len, FILE *fp)
{
if (fwrite(&len, 1, sizeof(len), fp) != sizeof(len))
elog(FATAL, "could not write init file");
if (fwrite(data, 1, len, fp) != len)
if (len > 0 && fwrite(data, 1, len, fp) != len)
elog(FATAL, "could not write init file");
}