--- contrib/pgcrypto/random.c
+++ contrib/pgcrypto/random.c
@@ -42,21 +42,28 @@
 #include <unistd.h>
 
 static int
-safe_read(int fd, void *buf, size_t count)
-{
-	int			done = 0;
-	char	   *p = buf;
-	int			res;
+safe_read(int fd, void *buf, size_t count) {
+#define NULL_MAX 16
+	int	done = 0;
+	char	*p = buf;
+	int	res, nulcount;
 
-	while (count)
-	{
+	nulcount = 0;
+	while (count) {
 		res = read(fd, p, count);
-		if (res <= 0)
-		{
+		if (res < 0) {
+			elog(WARNING, "RAND_DEV!%d res=%d errno=%d"
+				, count, res, errno);
 			if (errno == EINTR)
 				continue;
 			return -1;
-		}
+		} else if (res == 0) {
+			elog(WARNING, "RAND_DEV!%d NULL nulcount=%d"
+				, count, nulcount);
+			if (nulcount++ > NULL_MAX)
+				return -1;
+			usleep(1 << nulcount);
+		} else nulcount = 0;
 		p += res;
 		done += res;
 		count -= res;