Bug 824901 - HyperTextAccessible::DOMPointToHypertextOffset fails for node and offset equal to node child count, r=tbsaunde

accessible/src/generic/HyperTextAccessible.cpp

@@ -529,22 +529,32 @@ HyperTextAccessible::DOMPointToHypertextOffset(nsINode* aNode,
   } else {
     // findNode could be null if aNodeOffset == # of child nodes, which means
     // one of two things:
-    // 1) we're at the end of the children, keep findNode = null, so that we get
-    //    the last possible offset
-    // 2) there are no children and the passed-in node is mContent, which means
-    //    we're an aempty nsIAccessibleText
-    // 3) there are no children, and the passed-in node is not mContent -- use
+    // 1) there are no children, and the passed-in node is not mContent -- use
     //    parentContent for the node to find
+    // 2) there are no children and the passed-in node is mContent, which means
+    //    we're an empty nsIAccessibleText
+    // 3) there are children and we're at the end of the children
 
     findNode = aNode->GetChildAt(aNodeOffset);
-    if (!findNode && !aNodeOffset) {
-      if (aNode == GetNode()) {
-        // There are no children, which means this is an empty nsIAccessibleText, in which
-        // case we can only be at hypertext offset 0
-        *aHyperTextOffset = 0;
-        return nullptr;
+    if (!findNode) {
+      if (aNodeOffset == 0) {
+        if (aNode == GetNode()) {
+          // Case #1: this accessible has no children and thus has empty text,
+          // we can only be at hypertext offset 0.
+          *aHyperTextOffset = 0;
+          return nullptr;
+        }
+
+        // Case #2: there are no children, we're at this node.
+        findNode = aNode;
+      } else if (aNodeOffset == aNode->GetChildCount()) {
+        // Case #3: we're after the last child, get next node to this one.
+        for (nsINode* tmpNode = aNode;
+             !findNode && tmpNode && tmpNode != mContent;
+             tmpNode = tmpNode->GetParent()) {
+          findNode = tmpNode->GetNextSibling();
+        }
       }
-      findNode = aNode; // Case #2: there are no children
     }
   }
 

accessible/tests/mochitest/events.js

@@ -1266,6 +1266,38 @@ function synthSelectAll(aNodeOrID, aCheckerOrEventSeq)
   }
 }
 
+/**
+ * Move the caret in text accessible.
+ */
+function moveCaretToDOMPoint(aID, aNode, aOffset, aExpectedOffset,
+                             aFocusTargetID)
+{
+  this.target = getAccessible(aID, [nsIAccessibleText]);
+  this.focus = aFocusTargetID ? getAccessible(aFocusTargetID) : null;
+  this.focusNode = this.focus ? this.focus.DOMNode : null;
+
+  this.invoke = function moveCaretToDOMPoint_invoke()
+  {
+    if (this.focusNode)
+      this.focusNode.focus();
+
+    window.getSelection().getRangeAt(0).setStart(aNode, aOffset);
+  }
+
+  this.getID = function moveCaretToDOMPoint_getID()
+  {
+   return "Set caret on " + prettyName(aID) + " at point: " +
+     prettyName(aNode) + " node with offset " + aOffset;
+  }
+
+  this.eventSeq = [
+    new caretMoveChecker(aExpectedOffset, this.target)
+  ];
+
+  if (this.focus)
+    this.eventSeq.push(new asyncInvokerChecker(EVENT_FOCUS, this.focus));
+}
+
 /**
  * Set caret offset in text accessible.
  */

accessible/tests/mochitest/events/test_caretmove.html

@@ -77,6 +77,18 @@
       id = "p";
       gQueue.push(new synthTab(id, new caretMoveChecker(0, id)));
 
+      // Set caret after a child of span element, i.e. after 'text' text.
+      gQueue.push(new moveCaretToDOMPoint("test1", getNode("test1_span"), 1,
+                                           4, "test1"));
+      gQueue.push(new moveCaretToDOMPoint("test2", getNode("test2_span"), 1,
+                                           4, "test2"));
+
+      // empty text element
+      gQueue.push(new moveCaretToDOMPoint("test3", getNode("test3"), 0,
+                                           0, "test3"));
+      gQueue.push(new moveCaretToDOMPoint("test4", getNode("test4_span"), 0,
+                                           0, "test4"));
+
       gQueue.invoke(); // Will call SimpleTest.finish();
     }
 
@@ -90,7 +102,12 @@
   <a target="_blank"
      href="https://bugzilla.mozilla.org/show_bug.cgi?id=454377"
      title="Accessible caret move events testing">
-    Mozilla Bug 454377
+    Bug 454377
+  </a>
+  <a target="_blank"
+     href="https://bugzilla.mozilla.org/show_bug.cgi?id=824901"
+     title="HyperTextAccessible::DOMPointToHypertextOffset fails for node and offset equal to node child count">
+    Bug 824901
   </a>
   <p id="display"></p>
   <div id="content" style="display: none"></div>
@@ -102,6 +119,11 @@
   <p id="p" contentEditable="true"><span>text</span><br/>text</p>
   <div id="div" contentEditable="true"><p id="p1_in_div">text</p><p id="p2_in_div">text</p></div>
 
+  <p contentEditable="true" id="test1"><span id="test1_span">text</span>ohoho</p>
+  <p contentEditable="true" id="test2"><span><span id="test2_span">text</span></span>ohoho</p>
+  <p contentEditable="true" id="test3"></p>
+  <p contentEditable="true" id="test4"><span id="test4_span"></span></p>
+
   <div id="eventdump"></div>
 </body>
 </html>