Set tabindex for the comment form.

src/main/twirl/gitbucket/core/helper/preview.scala.html

@@ -8,6 +8,7 @@
   styleClass: String = "",
   placeholder: String = "Leave a comment",
   elastic: Boolean = false,
+  tabIndex: Int = -2,
   uid: Long = new java.util.Date().getTime())(implicit context: gitbucket.core.controller.Context)
 @import context._
 @import gitbucket.core._
@@ -22,6 +23,7 @@
       <span id="error-content" class="error"></span>
       @textarea = {
         <textarea id="content@uid" name="content" placeholder="@placeholder"
+          @if(tabIndex > -2){ tabindex="@tabIndex"}
           @if(style.nonEmpty){ style="@style"}
           @if(styleClass.nonEmpty){ class="@styleClass" }>@content</textarea>
       }

src/main/twirl/gitbucket/core/issues/commentform.scala.html

@@ -18,14 +18,15 @@
           enableTaskList     = true,
           hasWritePermission = hasWritePermission,
           style              = "",
-          elastic            = true
+          elastic            = true,
+          tabIndex           = 1
         )
         <div style="text-align: right;">
           <input type="hidden" name="issueId" value="@issue.issueId"/>
           @if((reopenable || !issue.closed) && (hasWritePermission || issue.openedUserName == loginAccount.get.userName)){
-            <input type="submit" class="btn" formaction="@url(repository)/issue_comments/state" value="@{if(issue.closed) "Reopen" else "Close"}" id="action"/>
+            <input type="submit" class="btn" tabindex="3" formaction="@url(repository)/issue_comments/state" value="@{if(issue.closed) "Reopen" else "Close"}" id="action"/>
           }
-          <input type="submit" class="btn btn-success" formaction="@url(repository)/issue_comments/new" value="Comment"/>
+          <input type="submit" class="btn btn-success" tabindex="2" formaction="@url(repository)/issue_comments/new" value="Comment"/>
         </div>
       </div>
     </div>