fixes #820

app/assets/javascripts/comments.js

@@ -25,9 +25,13 @@
         var $link = $(e.target);
         var $div = $link.closest("div.comments-for-post");
         var $textarea = $div.find("textarea")
-        $textarea.val($textarea.val() + "\n\n" + Danbooru.Comment.quote_message(data));
+        var msg = Danbooru.Comment.quote_message(data);
+        if ($textarea.val().length > 0) {
+          msg = $textarea.val() + "\n\n" + msg;
+        }
+        $textarea.val(msg);
         $div.find("a.expand-comment-response").trigger("click");
-        $textarea.focus();
+        $textarea.selectEnd();
       }
     );
     e.preventDefault();
@@ -51,7 +55,7 @@
     $("a.expand-comment-response").click(function(e) {
       $(e.target).hide();
       var $form = $(e.target).closest("div.new-comment").find("form");
-      $form.slideDown("fast");
+      $form.show();
       Danbooru.scroll_to($form);
       e.preventDefault();
     });

app/assets/javascripts/utility.js

@@ -73,4 +73,24 @@
     });
     return filtered;
   }
+  
+  $.fn.selectRange = function(start, end) {
+    return this.each(function() {
+      if (this.setSelectionRange) {
+        this.focus();
+        this.setSelectionRange(start, end);
+      } else if (this.createTextRange) {
+        var range = this.createTextRange();
+        range.collapse(true);
+        range.moveEnd('character', end);
+        range.moveStart('character', start);
+        range.select();
+      }
+    });
+  };
+  
+  $.fn.selectEnd = function(){
+    this.selectRange(this.val().length, this.val().length);
+    return this;
+  }
 })();

app/views/forum_posts/new.js.erb

@@ -1,6 +1,10 @@
-$("#forum_post_body").val($("#forum_post_body").val() + "\n\n" + <%= raw @forum_post.body.to_json %>);
+var msg = <%= raw @forum_post.body.to_json %>;
+if ($("#forum_post_body").val().length > 0) {
+  msg = $("#forum_post_body").val() + "\n\n" + msg;
+}
+$("#forum_post_body").val(msg);
 $("#topic-response").show();
-
 $('html, body').animate({
     scrollTop: $("#forum_post_body").offset().top - 100
 }, 500);
+$("#forum_post_body").selectEnd();