2 files changed, 9 insertions, 4 deletions

diff --git a/lib/libc/stdio/fread.c b/lib/libc/stdio/fread.c
index 851713be461f..6253856b9e33 100644
--- a/lib/libc/stdio/fread.c
+++ b/lib/libc/stdio/fread.c
@@ -67,9 +67,7 @@ __fread(void * __restrict buf, size_t size, size_t count, FILE * __restrict fp)
 	size_t total;
 
 	/*
-	 * The ANSI standard requires a return value of 0 for a count
-	 * or a size of 0.  Peculiarily, it imposes no such requirements
-	 * on fwrite; it only requires fread to be broken.
+	 * ANSI and SUSv2 require a return value of 0 if size or count are 0.
 	 */
 	if ((resid = count * size) == 0)
 		return (0);
diff --git a/lib/libc/stdio/fwrite.c b/lib/libc/stdio/fwrite.c
index 999d5958193d..cf52e42f615f 100644
--- a/lib/libc/stdio/fwrite.c
+++ b/lib/libc/stdio/fwrite.c
@@ -57,8 +57,15 @@ fwrite(buf, size, count, fp)
 	struct __suio uio;
 	struct __siov iov;
 
+	/*
+	 * ANSI and SUSv2 require a return value of 0 if size or count are 0.
+	 */
+	n = count * size;
+	if (n == 0)
+		return (0);
+
 	iov.iov_base = (void *)buf;
-	uio.uio_resid = iov.iov_len = n = count * size;
+	uio.uio_resid = iov.iov_len = n;
 	uio.uio_iov = &iov;
 	uio.uio_iovcnt = 1;