1 files changed, 20 insertions, 0 deletions
diff --git a/src/tests/userprog/write-zero.c b/src/tests/userprog/write-zero.c
new file mode 100644
index 0000000..d8dac9b
--- /dev/null
+++ b/src/tests/userprog/write-zero.c
@@ -0,0 +1,20 @@
+/* Try a 0-byte write, which should return 0 without writing
+   anything. */
+
+#include <syscall.h>
+#include "tests/lib.h"
+#include "tests/main.h"
+
+void
+test_main (void) 
+{
+  int handle, byte_cnt;
+  char buf;
+
+  CHECK ((handle = open ("sample.txt")) > 1, "open \"sample.txt\"");
+
+  buf = 123;
+  byte_cnt = write (handle, &buf, 0);
+  if (byte_cnt != 0)
+    fail("write() returned %d instead of 0", byte_cnt);
+}