1 files changed, 27 insertions, 0 deletions
diff --git a/libio/bug-mmap-fflush.c b/libio/bug-mmap-fflush.c
new file mode 100644
index 0000000000..984acb496b
--- /dev/null
+++ b/libio/bug-mmap-fflush.c
@@ -0,0 +1,27 @@
+/* Test for bug in fflush synchronization behavior.  */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+int main (void)
+{
+  FILE *f;
+  off_t o;
+  char buffer [1024];
+
+  system ("echo 'From foo@bar.com' > test");
+  f = fopen ("test", "r");
+  fseek (f, 0, SEEK_END);
+  o = ftello (f);
+  fseek (f, 0, SEEK_SET);
+  fflush (f);
+  system ("echo 'From bar@baz.edu' >> test");
+  fseek (f, o, SEEK_SET);
+  if (fgets (buffer, 1024, f) == NULL)
+    abort ();
+  if (strncmp (buffer, "From ", 5) != 0)
+    abort ();
+  fclose (f);
+  exit (0);
+}