Ensure placeholder uses func when its a lib.

fp/_baseConvert.js

@@ -1,6 +1,6 @@
 var mapping = require('./_mapping'),
     mutateMap = mapping.mutate,
-    placeholder = {};
+    fallbackHolder = {};
 
 /**
  * The base implementation of `convert` which accepts a `util` object of methods
@@ -40,7 +40,8 @@ function baseConvert(util, name, func, options) {
     'rearg': 'rearg' in options ? options.rearg : true
   };
 
-  var forceRearg = ('rearg' in options) && options.rearg;
+  var forceRearg = ('rearg' in options) && options.rearg,
+      placeholder = isLib ? func : fallbackHolder;
 
   var helpers = isLib ? func : {
     'ary': util.ary,

test/test-fp.js

@@ -715,7 +715,20 @@
   QUnit.module('placeholder methods');
 
   (function() {
-    QUnit.test('should support placeholders', function(assert) {
+    QUnit.test('should use `fp` as the default placeholder', function(assert) {
+      assert.expect(3);
+
+      var actual = fp.add(fp, 'b')('a');
+      assert.strictEqual(actual, 'ab');
+
+      actual = fp.slice(fp, 2)(1)(['a', 'b', 'c']);
+      assert.deepEqual(actual, ['b']);
+
+      actual = fp.fill(fp, 2)(1, '*')([1, 2, 3]);
+      assert.deepEqual(actual, [1, '*', 3]);
+    });
+
+    QUnit.test('should support `fp.placeholder`', function(assert) {
       assert.expect(6);
 
       _.each([[], fp.__], function(ph) {