Add a comment explaining that jQuery.map flattens arrays

diff --git a/src/core.js b/src/core.js
index 3389e83..3c7572f 100644 (file)
--- a/src/core.js
+++ b/src/core.js
@@ -726,6 +726,7 @@ jQuery.extend({
                        }
                }
 
+               // Flatten any nested arrays
                return ret.concat.apply( [], ret );
        },