Ensure _.ary treats negative n values as 0.

lodash.src.js

@@ -6683,7 +6683,7 @@
       if (guard && isIterateeCall(func, n, guard)) {
         n = null;
       }
-      n = n == null ? func.length : (+n || 0);
+      n = (func && n == null) ? func.length : nativeMax(+n || 0, 0);
       return createWrapper(func, ARY_FLAG, null, null, null, null, n);
     }
 

test/test.js

@@ -896,6 +896,16 @@
       deepEqual(capped('a', 'b', 'c', 'd'), ['a', 'b', 'c']);
     });
 
+    test('should treat a negative `n` as `0`', 1, function() {
+      var capped = _.ary(fn, -1);
+
+      try {
+        var actual = capped('a');
+      } catch(e) {}
+
+      deepEqual(actual, []);
+    });
+
     test('should work when provided less than the capped numer of arguments', 1, function() {
       var capped = _.ary(fn, 3);
       deepEqual(capped('a'), ['a']);