supplement deleted function when operate conficts

@@ -101,7 +101,8 @@ gulp.task('compass-production', ['assets'], function() {
                 image: distDir.img,
                 font: distDir.font,
                 http_path: '/',
-                style: 'compressed'
+                style: 'compressed',
+                sourcemap: false
             })
         )
         .on('error', function(error) {
@@ -166,7 +167,7 @@ gulp.task('concat-min-libs', ['pre-libs'], function() {
 
     fs.writeFileSync(path, jsStr.substr(jsStr.indexOf('});') + 4));
 
-    return gulp.src(['js/sea.js', distDir.js + '/libs.js'])
+    return gulp.src(['plugin/sea.js', distDir.js + '/libs.js'])
         .pipe(concat('lib.js'))
         .pipe(uglify())
         .pipe(gulp.dest(distDir.js));

@@ -6,6 +6,8 @@
 
 var $ = require('yoho.jquery');
 
+var $returnTop = $('.return-top');
+
 var apiDomain;
 
 /**
@@ -126,6 +128,39 @@ function actionhomeFootChange() {
     });
 }
 
+function rePosReturn() {
+    if ($(window).height() < $(document).height()) {
+        $returnTop.removeClass('hide');
+    } else {
+        $returnTop.addClass('hide');
+    }
+}
+
+//返回顶部
+$returnTop.click(function() {
+    $('html,body').animate({
+        scrollTop: 0
+    }, 500);
+});
+
+$(window).scroll(function() {
+    if ($(window).scrollTop() === 0) {
+        $returnTop.addClass('hide');
+    } else {
+        $returnTop.removeClass('hide');
+    }
+});
+
+rePosReturn();
+
+//如果初始是隐藏的，监听图片加载，重新确定return-top的高度
+if ($returnTop.hasClass('hide')) {
+    $('img').load(rePosReturn);
+}
+
 //初始化
 actionSubscription();
 actionhomeFootChange();
+
+//暴露给有可能通AJAX改变内容的页面去用
+window.rePosReturnTop = rePosReturn;
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