diff options
Diffstat (limited to 'src/common/psprintf.c')
| -rw-r--r-- | src/common/psprintf.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/src/common/psprintf.c b/src/common/psprintf.c index 04465a18e69..2cf100f0954 100644 --- a/src/common/psprintf.c +++ b/src/common/psprintf.c @@ -45,6 +45,7 @@ char * psprintf(const char *fmt,...) { + int save_errno = errno; size_t len = 128; /* initial assumption about buffer size */ for (;;) @@ -60,6 +61,7 @@ psprintf(const char *fmt,...) result = (char *) palloc(len); /* Try to format the data. */ + errno = save_errno; va_start(args, fmt); newlen = pvsnprintf(result, len, fmt, args); va_end(args); @@ -89,6 +91,9 @@ psprintf(const char *fmt,...) * Other error cases do not return, but exit via elog(ERROR) or exit(). * Hence, this shouldn't be used inside libpq. * + * Caution: callers must be sure to preserve their entry-time errno + * when looping, in case the fmt contains "%m". + * * Note that the semantics of the return value are not exactly C99's. * First, we don't promise that the estimated buffer size is exactly right; * callers must be prepared to loop multiple times to get the right size. |