diff --git a/editor/libeditor/HTMLEditRules.cpp b/editor/libeditor/HTMLEditRules.cpp
index be7ab8b2b342..7ca00d0aba3d 100644
--- a/editor/libeditor/HTMLEditRules.cpp
+++ b/editor/libeditor/HTMLEditRules.cpp
@@ -4806,6 +4806,24 @@ HTMLEditRules::WillHTMLIndent(bool* aCancel,
     return rv;
   }
 
+  // IndentAroundSelectionWithHTML() creates AutoSelectionRestorer.
+  // Therefore, even if it returns NS_OK, editor might have been destroyed
+  // at restoring Selection.
+  rv = IndentAroundSelectionWithHTML();
+  if (NS_WARN_IF(!CanHandleEditAction())) {
+    return NS_ERROR_EDITOR_DESTROYED;
+  }
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+  return NS_OK;
+}
+
+nsresult
+HTMLEditRules::IndentAroundSelectionWithHTML()
+{
+  MOZ_ASSERT(IsEditorDataAvailable());
+
   AutoSelectionRestorer selectionRestorer(&SelectionRef(), &HTMLEditorRef());
 
   // convert the selection ranges into "promoted" selection ranges:
@@ -4818,8 +4836,9 @@ HTMLEditRules::WillHTMLIndent(bool* aCancel,
 
   // use these ranges to contruct a list of nodes to act on.
   nsTArray<OwningNonNull<nsINode>> arrayOfNodes;
-  rv = GetNodesForOperation(arrayOfRanges, arrayOfNodes, EditAction::indent,
-                            TouchContent::yes);
+  nsresult rv =
+    GetNodesForOperation(arrayOfRanges, arrayOfNodes, EditAction::indent,
+                         TouchContent::yes);
   if (NS_WARN_IF(NS_FAILED(rv))) {
     return rv;
   }
@@ -4846,6 +4865,9 @@ HTMLEditRules::WillHTMLIndent(bool* aCancel,
     RefPtr<Element> theBlock =
       HTMLEditorRef().CreateNodeWithTransaction(*nsGkAtoms::blockquote,
                                                 splitNodeResult.SplitPoint());
+    if (NS_WARN_IF(!CanHandleEditAction())) {
+      return NS_ERROR_EDITOR_DESTROYED;
+    }
     if (NS_WARN_IF(!theBlock)) {
       return NS_ERROR_FAILURE;
     }
@@ -4855,18 +4877,23 @@ HTMLEditRules::WillHTMLIndent(bool* aCancel,
     while (!arrayOfNodes.IsEmpty()) {
       OwningNonNull<nsINode> curNode = arrayOfNodes[0];
       rv = HTMLEditorRef().DeleteNodeWithTransaction(*curNode);
+      if (NS_WARN_IF(!CanHandleEditAction())) {
+        return NS_ERROR_EDITOR_DESTROYED;
+      }
       if (NS_WARN_IF(NS_FAILED(rv))) {
         return rv;
       }
       arrayOfNodes.RemoveElementAt(0);
     }
-    // put selection in new block
-    *aHandled = true;
     EditorRawDOMPoint atStartOfTheBlock(theBlock, 0);
-    ErrorResult error;
-    SelectionRef().Collapse(atStartOfTheBlock, error);
     // Don't restore the selection
     selectionRestorer.Abort();
+    ErrorResult error;
+    SelectionRef().Collapse(atStartOfTheBlock, error);
+    if (NS_WARN_IF(!CanHandleEditAction())) {
+      error.SuppressException();
+      return NS_ERROR_EDITOR_DESTROYED;
+    }
     if (NS_WARN_IF(!error.Failed())) {
       return error.StealNSResult();
     }
@@ -4903,6 +4930,9 @@ HTMLEditRules::WillHTMLIndent(bool* aCancel,
         rv = HTMLEditorRef().MoveNodeWithTransaction(
                                *curNode->AsContent(),
                                EditorRawDOMPoint(sibling, 0));
+        if (NS_WARN_IF(!CanHandleEditAction())) {
+          return NS_ERROR_EDITOR_DESTROYED;
+        }
         if (NS_WARN_IF(NS_FAILED(rv))) {
           return rv;
         }
@@ -4920,6 +4950,9 @@ HTMLEditRules::WillHTMLIndent(bool* aCancel,
             sibling->NodeInfo()->NamespaceID()) {
         rv = HTMLEditorRef().MoveNodeToEndWithTransaction(*curNode->AsContent(),
                                                           *sibling);
+        if (NS_WARN_IF(!CanHandleEditAction())) {
+          return NS_ERROR_EDITOR_DESTROYED;
+        }
         if (NS_WARN_IF(NS_FAILED(rv))) {
           return rv;
         }
@@ -4946,6 +4979,9 @@ HTMLEditRules::WillHTMLIndent(bool* aCancel,
         curList =
           HTMLEditorRef().CreateNodeWithTransaction(
                             *containerName, splitNodeResult.SplitPoint());
+        if (NS_WARN_IF(!CanHandleEditAction())) {
+          return NS_ERROR_EDITOR_DESTROYED;
+        }
         if (NS_WARN_IF(!curList)) {
           return NS_ERROR_FAILURE;
         }
@@ -4956,6 +4992,9 @@ HTMLEditRules::WillHTMLIndent(bool* aCancel,
       // tuck the node into the end of the active list
       rv = HTMLEditorRef().MoveNodeToEndWithTransaction(*curNode->AsContent(),
                                                         *curList);
+      if (NS_WARN_IF(!CanHandleEditAction())) {
+        return NS_ERROR_EDITOR_DESTROYED;
+      }
       if (NS_WARN_IF(NS_FAILED(rv))) {
         return rv;
       }
@@ -5002,12 +5041,18 @@ HTMLEditRules::WillHTMLIndent(bool* aCancel,
         curList =
           HTMLEditorRef().CreateNodeWithTransaction(
                             *containerName, splitNodeResult.SplitPoint());
+        if (NS_WARN_IF(!CanHandleEditAction())) {
+          return NS_ERROR_EDITOR_DESTROYED;
+        }
         if (NS_WARN_IF(!curList)) {
           return NS_ERROR_FAILURE;
         }
       }
 
       rv = HTMLEditorRef().MoveNodeToEndWithTransaction(*listItem, *curList);
+      if (NS_WARN_IF(!CanHandleEditAction())) {
+        return NS_ERROR_EDITOR_DESTROYED;
+      }
       if (NS_WARN_IF(NS_FAILED(rv))) {
         return rv;
       }
@@ -5042,6 +5087,9 @@ HTMLEditRules::WillHTMLIndent(bool* aCancel,
       curQuote =
         HTMLEditorRef().CreateNodeWithTransaction(*nsGkAtoms::blockquote,
                                                   splitNodeResult.SplitPoint());
+      if (NS_WARN_IF(!CanHandleEditAction())) {
+        return NS_ERROR_EDITOR_DESTROYED;
+      }
       if (NS_WARN_IF(!curQuote)) {
         return NS_ERROR_FAILURE;
       }
@@ -5053,6 +5101,9 @@ HTMLEditRules::WillHTMLIndent(bool* aCancel,
     // tuck the node into the end of the active blockquote
     rv = HTMLEditorRef().MoveNodeToEndWithTransaction(*curNode->AsContent(),
                                                       *curQuote);
+    if (NS_WARN_IF(!CanHandleEditAction())) {
+      return NS_ERROR_EDITOR_DESTROYED;
+    }
     if (NS_WARN_IF(NS_FAILED(rv))) {
       return rv;
     }
diff --git a/editor/libeditor/HTMLEditRules.h b/editor/libeditor/HTMLEditRules.h
index e462cd3c39ef..e17ede38c371 100644
--- a/editor/libeditor/HTMLEditRules.h
+++ b/editor/libeditor/HTMLEditRules.h
@@ -329,7 +329,15 @@ protected:
   nsresult WillRemoveList(bool aOrdered, bool* aCancel, bool* aHandled);
   nsresult WillIndent(bool* aCancel, bool* aHandled);
   nsresult WillCSSIndent(bool* aCancel, bool* aHandled);
-  nsresult WillHTMLIndent(bool* aCancel, bool* aHandled);
+
+  /**
+   * Called before indenting around Selection and it's not in CSS mode.
+   * This method actually tries to indent the contents.
+   *
+   * @param aCancel             Returns true if the operation is canceled.
+   * @param aHandled            Returns true if the edit action is handled.
+   */
+  MOZ_MUST_USE nsresult WillHTMLIndent(bool* aCancel, bool* aHandled);
 
   /**
    * Called before outdenting around Selection.  This method actually tries
@@ -537,6 +545,14 @@ protected:
   MOZ_MUST_USE nsresult
   AfterEditInner(EditAction action, nsIEditor::EDirection aDirection);
 
+  /**
+   * IndentAroundSelectionWithHTML() indents around Selection with HTML.
+   * This method creates AutoSelectionRestorer.  Therefore, each caller
+   * need to check if the editor is still available even if this returns
+   * NS_OK.
+   */
+  MOZ_MUST_USE nsresult IndentAroundSelectionWithHTML();
+
   /**
    * OutdentAroundSelection() outdents contents around Selection.
    * This method creates AutoSelectionRestorer.  Therefore, each caller