Bug 1860210 - Make `HTMLEditUtils::GetPreviousEditablePoint` and `HTMLEditUtils::GetNextEditablePoint` check ancestor limiter before getting a sibling of ancestor r=m_kato

They check ancestor limiter when they are climbing up the DOM tree if and only
if the ancestor does not have a sibling.  However, this causes moving into
a sibling of the ancestor limiter.

Differential Revision: https://phabricator.services.mozilla.com/D192528

editor/libeditor/HTMLEditUtils.cpp

@@ -1667,6 +1667,10 @@ EditorDOMPointType HTMLEditUtils::GetPreviousEditablePoint(
                "HTMLEditUtils::GetPreviousEditablePoint() may return a point "
                "between table structure elements");
 
+  if (&aContent == aAncestorLimiter) {
+    return EditorDOMPointType();
+  }
+
   // First, look for previous content.
   nsIContent* previousContent = aContent.GetPreviousSibling();
   if (!previousContent) {
@@ -1675,12 +1679,10 @@ EditorDOMPointType HTMLEditUtils::GetPreviousEditablePoint(
     }
     nsIContent* inclusiveAncestor = &aContent;
     for (Element* parentElement : aContent.AncestorsOfType<Element>()) {
-      previousContent = parentElement->GetPreviousSibling();
-      if (!previousContent &&
-          (parentElement == aAncestorLimiter ||
+      if (parentElement == aAncestorLimiter ||
           !HTMLEditUtils::IsSimplyEditableNode(*parentElement) ||
           !HTMLEditUtils::CanCrossContentBoundary(*parentElement,
-                                                   aHowToTreatTableBoundary))) {
+                                                  aHowToTreatTableBoundary)) {
         // If cannot cross the parent element boundary, return the point of
         // last inclusive ancestor point.
         return EditorDOMPointType(inclusiveAncestor);
@@ -1693,6 +1695,7 @@ EditorDOMPointType HTMLEditUtils::GetPreviousEditablePoint(
         inclusiveAncestor = parentElement;
       }
 
+      previousContent = parentElement->GetPreviousSibling();
       if (!previousContent) {
         continue;  // Keep looking for previous sibling of an ancestor.
       }
@@ -1777,6 +1780,10 @@ EditorDOMPointType HTMLEditUtils::GetNextEditablePoint(
                "HTMLEditUtils::GetPreviousEditablePoint() may return a point "
                "between table structure elements");
 
+  if (&aContent == aAncestorLimiter) {
+    return EditorDOMPointType();
+  }
+
   // First, look for next content.
   nsIContent* nextContent = aContent.GetNextSibling();
   if (!nextContent) {
@@ -1785,19 +1792,10 @@ EditorDOMPointType HTMLEditUtils::GetNextEditablePoint(
     }
     nsIContent* inclusiveAncestor = &aContent;
     for (Element* parentElement : aContent.AncestorsOfType<Element>()) {
-      // End of the parent element is a next editable point if it's an
-      // element which is not a table structure element.
-      if (!HTMLEditUtils::IsAnyTableElement(parentElement) ||
-          HTMLEditUtils::IsTableCellOrCaption(*parentElement)) {
-        inclusiveAncestor = parentElement;
-      }
-
-      nextContent = parentElement->GetNextSibling();
-      if (!nextContent &&
-          (parentElement == aAncestorLimiter ||
+      if (parentElement == aAncestorLimiter ||
           !HTMLEditUtils::IsSimplyEditableNode(*parentElement) ||
           !HTMLEditUtils::CanCrossContentBoundary(*parentElement,
-                                                   aHowToTreatTableBoundary))) {
+                                                  aHowToTreatTableBoundary)) {
         // If cannot cross the parent element boundary, return the point of
         // last inclusive ancestor point.
         return EditorDOMPointType(inclusiveAncestor);
@@ -1810,6 +1808,7 @@ EditorDOMPointType HTMLEditUtils::GetNextEditablePoint(
         inclusiveAncestor = parentElement;
       }
 
+      nextContent = parentElement->GetNextSibling();
       if (!nextContent) {
         continue;  // Keep looking for next sibling of an ancestor.
       }

testing/web-platform/tests/input-events/input-events-get-target-ranges-backspace.tentative.html

@@ -2062,4 +2062,70 @@ promise_test(async (t) => {
   checkGetTargetRangesOfInputOnDeleteSomething();
 }, 'Meta + Backspace at "<p>   abc[] def</p>"');
 
+// If editing host is nested, editing in the nested one shouldn't cause
+// target ranges extended to outside of it.
+promise_test(async t => {
+  const innerHTML = "<div contenteditable=\"false\"><div contenteditable=\"\"><p><br></p></div></div>";
+  initializeTest(innerHTML);
+  const p = gEditor.querySelector("p");
+  const innerEditingHost = p.parentNode;
+  document.activeElement?.blur();
+  p.parentNode.focus();
+  gSelection.collapse(p, 0);
+  await sendBackspaceKey();
+  if (gEditor.innerHTML == innerHTML) {
+    checkGetTargetRangesOfBeforeinputOnDeleteSomething({
+      startContainer: p,
+      startOffset: 0,
+      endContainer: p,
+      endOffset: 0,
+    });
+    checkGetTargetRangesOfInputOnDoNothing();
+  } else {
+    checkEditorContentResultAsSubTest(
+      "<div contenteditable=\"false\"><div contenteditable=\"\"><br></div></div>",
+      t.name
+    );
+    checkGetTargetRangesOfBeforeinputOnDeleteSomething({
+      startContainer: innerEditingHost,
+      startOffset: 0,
+      endContainer: p,
+      endOffset: 1,
+    });
+    checkGetTargetRangesOfInputOnDeleteSomething();
+  }
+}, 'Backspace at "<div contenteditable="false"><div contenteditable=""><p>{}<br></p></div></div>');
+
+promise_test(async t => {
+  const innerHTML = "<div contenteditable=\"false\">\n  <div contenteditable=\"\"><p><br></p></div></div>";
+  initializeTest(innerHTML);
+  const p = gEditor.querySelector("p");
+  const innerEditingHost = p.parentNode;
+  document.activeElement?.blur();
+  p.parentNode.focus();
+  gSelection.collapse(p, 0);
+  await sendBackspaceKey();
+  if (gEditor.innerHTML == innerHTML) {
+    checkGetTargetRangesOfBeforeinputOnDeleteSomething({
+      startContainer: p,
+      startOffset: 0,
+      endContainer: p,
+      endOffset: 0,
+    });
+    checkGetTargetRangesOfInputOnDoNothing();
+  } else {
+    checkEditorContentResultAsSubTest(
+      "<div contenteditable=\"false\">\n  <div contenteditable=\"\"><br></div></div>",
+      t.name
+    );
+    checkGetTargetRangesOfBeforeinputOnDeleteSomething({
+      startContainer: innerEditingHost,
+      startOffset: 0,
+      endContainer: p,
+      endOffset: 1,
+    });
+    checkGetTargetRangesOfInputOnDeleteSomething();
+  }
+}, 'Backspace at "<div contenteditable="false">\n  <div contenteditable=""><p>{}<br></p></div></div>');
+
 </script>