diff options
Diffstat (limited to 'src/interfaces/libpq/pqexpbuffer.c')
| -rw-r--r-- | src/interfaces/libpq/pqexpbuffer.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/src/interfaces/libpq/pqexpbuffer.c b/src/interfaces/libpq/pqexpbuffer.c index 0814ec6dbe0..43c36c3bff8 100644 --- a/src/interfaces/libpq/pqexpbuffer.c +++ b/src/interfaces/libpq/pqexpbuffer.c @@ -233,6 +233,7 @@ enlargePQExpBuffer(PQExpBuffer str, size_t needed) void printfPQExpBuffer(PQExpBuffer str, const char *fmt,...) { + int save_errno = errno; va_list args; bool done; @@ -244,6 +245,7 @@ printfPQExpBuffer(PQExpBuffer str, const char *fmt,...) /* Loop in case we have to retry after enlarging the buffer. */ do { + errno = save_errno; va_start(args, fmt); done = appendPQExpBufferVA(str, fmt, args); va_end(args); @@ -261,6 +263,7 @@ printfPQExpBuffer(PQExpBuffer str, const char *fmt,...) void appendPQExpBuffer(PQExpBuffer str, const char *fmt,...) { + int save_errno = errno; va_list args; bool done; @@ -270,6 +273,7 @@ appendPQExpBuffer(PQExpBuffer str, const char *fmt,...) /* Loop in case we have to retry after enlarging the buffer. */ do { + errno = save_errno; va_start(args, fmt); done = appendPQExpBufferVA(str, fmt, args); va_end(args); @@ -281,6 +285,9 @@ appendPQExpBuffer(PQExpBuffer str, const char *fmt,...) * Shared guts of printfPQExpBuffer/appendPQExpBuffer. * Attempt to format data and append it to str. Returns true if done * (either successful or hard failure), false if need to retry. + * + * Caution: callers must be sure to preserve their entry-time errno + * when looping, in case the fmt contains "%m". */ static bool appendPQExpBufferVA(PQExpBuffer str, const char *fmt, va_list args) |