Check for an error when opening "/dev/urandom". Otherwise wrong error is returned e.g. if the open file limit is reached.

Author: dmitry-starodubov

src/common/os/posix/guid.cpp

@@ -45,6 +45,9 @@ void GenerateRandomBytes(void* buffer, FB_SIZE_T size)
 {
 	// do not use /dev/random because it may return lesser data than we need.
 	int fd = os_utils::open("/dev/urandom", O_RDONLY);
+	if (fd < 0)
+		Firebird::system_call_failed::raise("open");
+
 	for (FB_SIZE_T offset = 0; offset < size; )
 	{
 		int rc = read(fd, static_cast<char*>(buffer) + offset, size - offset);