DevTools: fix text offset when selection ends on expand triangle

third_party/WebKit/Source/devtools/front_end/console/ConsoleViewport.js

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 425 matching lines @@
     if (startSelection.node && startSelection.node.isSelfOrDescendant(startSelectionElement)) {
       var itemTextOffset = this._textOffsetInNode(startSelectionElement, startSelection.node, startSelection.offset);
       textLines[0] = textLines[0].substring(itemTextOffset);
     }
 
     return textLines.join('\n');
   }
 
   /**
    * @param {!Element} itemElement
-   * @param {!Node} container
+   * @param {!Node} selectionNode
    * @param {number} offset
    * @return {number}
    */
-  _textOffsetInNode(itemElement, container, offset) {
-    if (container.nodeType !== Node.TEXT_NODE) {
-      if (offset < container.childNodes.length) {
-        container = /** @type {!Node} */ (container.childNodes.item(offset));
+  _textOffsetInNode(itemElement, selectionNode, offset) {
+    // If the selectionNode is not a TextNode, we may need to convert a child offset into a character offset.
+    if (selectionNode.nodeType !== Node.TEXT_NODE) {
+      if (offset < selectionNode.childNodes.length) {
+        selectionNode = /** @type {!Node} */ (selectionNode.childNodes.item(offset));
         offset = 0;
       } else {
-        offset = container.textContent.length;
+        offset = selectionNode.textContent.length;
       }
     }
+    // This method traverses TextNodes until reaching the selectionNode. This fails if selectionNode is before the first
+    // TextNode. We can move the selectionNode to the next TextNode to avoid this case, which may happen if a text
+    // selection ends on an expand triangle icon.
+    if (!selectionNode.textContent.length)
+      selectionNode = selectionNode.traverseNextTextNode(itemElement) || selectionNode;
 
     var chars = 0;
     var node = itemElement;
-    while ((node = node.traverseNextTextNode(itemElement)) && !node.isSelfOrDescendant(container))
+    while ((node = node.traverseNextTextNode(itemElement)) && !node.isSelfOrDescendant(selectionNode))

[lushnikov, 2017/05/05 23:31:57]

let's use node.traverseNextNode(itemElement) to fix the stop condition.
You won't need the cryptic if-condition in this case.

[luoe, 2017/05/05 23:48:51]

Done.

       chars += Components.Linkifier.untruncatedNodeText(node).length;
     // If the selection offset is at the end of a link's ellipsis, use the untruncated length as offset.
-    var untruncatedContainerLength = Components.Linkifier.untruncatedNodeText(container).length;
+    var untruncatedContainerLength = Components.Linkifier.untruncatedNodeText(selectionNode).length;
     if (offset === 1 && untruncatedContainerLength > offset)
       offset = untruncatedContainerLength;
     return chars + offset;
   }
 
   /**
    * @param {!Event} event
    */
   _onScroll(event) {
     this.refresh();
@@ skipping 125 matching lines @@
 Console.ConsoleViewportElement.prototype = {
   willHide() {},
 
   wasShown() {},
 
   /**
    * @return {!Element}
    */
   element() {},
 };