DevTools: fix text offset when selection ends on expand triangle

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

Index: third_party/WebKit/Source/devtools/front_end/console/ConsoleViewport.js
diff --git a/third_party/WebKit/Source/devtools/front_end/console/ConsoleViewport.js b/third_party/WebKit/Source/devtools/front_end/console/ConsoleViewport.js
index b98dc1c4252cbf47dbf61172efd63861d6072453..7730c06b484e60aa5a8b88035b0c499aa940eb6d 100644
--- a/third_party/WebKit/Source/devtools/front_end/console/ConsoleViewport.js
+++ b/third_party/WebKit/Source/devtools/front_end/console/ConsoleViewport.js
@@ -448,6 +448,7 @@ Console.ConsoleViewport = class {
    * @return {number}
    */
   _textOffsetInNode(itemElement, container, offset) {

[einbinder, 2017/05/03 01:07:48]

These names are confusing because the itemElement contains the container. Maybe
call it selection node?

[luoe, 2017/05/03 02:58:39]

Done.

+    // If the container is not a TextNode, we may need to convert a child offset into a character offset.
     if (container.nodeType !== Node.TEXT_NODE) {
       if (offset < container.childNodes.length) {
         container = /** @type {!Node} */ (container.childNodes.item(offset));
@@ -456,6 +457,14 @@ Console.ConsoleViewport = class {
         offset = container.textContent.length;
       }
     }
+    // This method traverses TextNodes until the container is reached. This fails if the container is before the first
+    // TextNode. We can move the container to the next TextNode to avoid this case, which may happen if a text selection
+    // ends on an expand triangle icon.
+    if (container.textContent.length === 0 && container.nodeType !== Node.TEXT_NODE) {

[einbinder, 2017/05/03 01:07:48]

!container.textContent.length? I don't like the idea of selection being in an
empty text node

[luoe, 2017/05/03 02:58:39]

Done.

+      var nextTextNode = container.traverseNextTextNode(itemElement);
+      if (nextTextNode)
+        container = nextTextNode;

[einbinder, 2017/05/03 01:07:48]

This works, but it feels uncomfortable to not have an else here

[luoe, 2017/05/03 02:58:39]

I can see that it seems strange at first on first glance, "If we're supposed to
move the container, wouldn't something break if that fails?"  But we don't
actually need to change the container if there is no next text node.

Perhaps it reads better as
      selectionNode = selectionNode.traverseNextTextNode(itemElement) ||
selectionNode;
?

[einbinder, 2017/05/03 05:15:23]

I guess its fine the way it was.

+    }
 
     var chars = 0;
     var node = itemElement;