library: Support external libraries that modify Array.prototype

While a somewhat-dangerous practice, existing users do do this,
and we shouldn't abort on it. Using hasOwnProperty is a simple
way to make sure we're checking the dense array itself, not the
prototype.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/library.js b/src/library.js
index 53ebbf15..0a8e862a 100644
--- a/src/library.js
+++ b/src/library.js
@@ -52,7 +52,7 @@ LibraryManager.library = {
     streams: [null],
 #if ASSERTIONS
     checkStreams: function() {
-      for (var i in FS.streams) assert(i >= 0 && i < FS.streams.length); // no keys not in dense span
+      for (var i in FS.streams) if (FS.streams.hasOwnProperty(i)) assert(i >= 0 && i < FS.streams.length); // no keys not in dense span
       for (var i = 0; i < FS.streams.length; i++) assert(typeof FS.streams[i] == 'object'); // no non-null holes in dense span
     },
 #endif