Ensure that fileno() returns -1 when given an invalid file pointer.

1 files changed, 3 insertions, 1 deletions

diff --git a/src/library.js b/src/library.js
index 5df5ff20..b9571a73 100644
--- a/src/library.js
+++ b/src/library.js
@@ -2420,7 +2420,9 @@ LibraryManager.library = {
   fileno: function(stream) {
     // int fileno(FILE *stream);
     // http://pubs.opengroup.org/onlinepubs/000095399/functions/fileno.html
-    return FS.getStreamFromPtr(stream).fd;
+    stream = FS.getStreamFromPtr(stream);
+    if (!stream) return -1;
+    return stream.fd;
   },
   ftrylockfile: function() {
     // int ftrylockfile(FILE *file);