Show users what's wrong when they try to edit an inline with an editor already open

Summary: Fixes T8572. Ideally we would probably just permit this, but clean up the behavior until the day arrives when inline code is actually rewritten.

Test Plan:
  - Tried to launch editors in Differential and Diffusion while comments were already open.
  - Verified that "Jump to inline" works in both cases.

{F788008}

{F788009}

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T8572

Differential Revision: https://secure.phabricator.com/D14094

webroot/rsrc/js/application/differential/DifferentialInlineCommentEditor.js

@@ -250,12 +250,30 @@ JX.install('DifferentialInlineCommentEditor', {
       JX.DifferentialInlineCommentEditor._undoRows = rows;
     },
 
-    start : function() {
-      this._registerUndoListener();
+    _onBusyWorkflow: function() {
+      // If the user clicks the "Jump to Inline" button, scroll to the row
+      // being edited.
+      JX.DOM.scrollTo(this.getRow());
+    },
 
-      var data = this._buildRequestData();
+    start : function() {
       var op = this.getOperation();
 
+      // The user is already editing a comment, we're going to give them an
+      // error message.
+      if (op == 'busy') {
+        var onbusy = JX.bind(this, this._onBusyWorkflow);
+
+        new JX.Workflow(this._uri, {op: op})
+          .setHandler(onbusy)
+          .start();
+
+        return this;
+      }
+
+      this._registerUndoListener();
+      var data = this._buildRequestData();
+
       if (op == 'delete' || op == 'refdelete' || op == 'undelete') {
         this._setRowState('loading');
 

webroot/rsrc/js/application/differential/behavior-edit-inline-comments.js

@@ -138,13 +138,23 @@ JX.behavior('differential-edit-inline-comments', function(config) {
     'mousedown',
     ['differential-changeset', 'tag:th'],
     function(e) {
-      if (editor  ||
-          selecting ||
-          e.isRightButton() ||
+      if (e.isRightButton() ||
           getRowNumber(e.getTarget()) === undefined) {
         return;
       }
 
+      if (editor) {
+        new JX.DifferentialInlineCommentEditor(config.uri)
+          .setOperation('busy')
+          .setRow(editor.getRow().previousSibling)
+          .start();
+        return;
+      }
+
+      if (selecting) {
+        return;
+      }
+
       selecting = true;
       root = e.getNode('differential-changeset');