From b2e66c86f685678106fbfd91a7b4d9a08d852da5 Mon Sep 17 00:00:00 2001
From: Masayuki Nakano <masayuki@d-toybox.com>
Date: Sat, 8 Mar 2025 22:31:57 +0000
Subject: [PATCH] Bug 1940377 - part 8: Make `HTMLEditor` stop normalizing
 white-spaces during initialization r=m_kato

Enabling the new normalizer causes this assertion failure:
```
###!!! ASSERTION: Want to fire DOMNodeRemoved event, but it's not safe: 'Error', file /builds/worker/checkouts/gecko/dom/base/nsContentUtils.cpp:5586
#01: NS_DebugBreak [xpcom/base/nsDebugImpl.cpp:508]
#02: nsContentUtils::MaybeFireNodeRemoved(nsINode*, nsINode*) [dom/base/nsContentUtils.cpp:5587]
#03: nsINode::RemoveChild(nsINode&, mozilla::ErrorResult&) [dom/base/nsINode.cpp:0]
#04: mozilla::DeleteNodeTransaction::DoTransaction() [editor/libeditor/DeleteNodeTransaction.cpp:112]
#05: mozilla::EditorBase::DoTransactionInternal(nsITransaction*) [editor/libeditor/EditorBase.cpp:929]
#06: mozilla::EditorBase::DeleteNodeWithTransaction(nsIContent&) [editor/libeditor/EditorBase.cpp:2685]
#07: mozilla::WhiteSpaceVisibilityKeeper::NormalizeWhiteSpacesToSplitTextNodeAt(mozilla::HTMLEditor&, mozilla::EditorDOMPointBase<RefPtr<mozilla::dom::Text>, nsIContent*> const&, mozilla::EnumSet<mozilla::WhiteSpaceVisibilityKeeper::NormalizeOption, unsigned int>) [editor/libeditor/WhiteSpaceVisibilityKeeper.cpp:1384]
#08: mozilla::WhiteSpaceVisibilityKeeper::NormalizeWhiteSpacesToSplitAt(mozilla::HTMLEditor&, mozilla::EditorDOMPointBase<nsCOMPtr<nsINode>, nsCOMPtr<nsIContent> > const&, mozilla::EnumSet<mozilla::WhiteSpaceVisibilityKeeper::NormalizeOption, unsigned int>) [editor/libeditor/WhiteSpaceVisibilityKeeper.cpp:1599]
#09: mozilla::HTMLEditor::PrepareToInsertLineBreak(mozilla::HTMLEditor::LineBreakType, mozilla::EditorDOMPointBase<nsCOMPtr<nsINode>, nsCOMPtr<nsIContent> > const&) [editor/libeditor/HTMLEditor.cpp:4418]
#10: mozilla::EditorBase::InsertPaddingBRElementForEmptyLastLineWithTransaction(mozilla::EditorDOMPointBase<nsCOMPtr<nsINode>, nsCOMPtr<nsIContent> > const&) [editor/libeditor/EditorBase.cpp:2511]
#11: mozilla::HTMLEditor::InsertBRElementToEmptyListItemsAndTableCellsInRange(mozilla::RangeBoundaryBase<nsINode*, nsIContent*> const&, mozilla::RangeBoundaryBase<nsINode*, nsIContent*> const&) [editor/libeditor/HTMLEditSubActionHandler.cpp:0]
#12: mozilla::HTMLEditor::InitEditorContentAndSelection() [editor/libeditor/HTMLEditSubActionHandler.cpp:187]
#13: mozilla::HTMLEditor::Init(mozilla::dom::Document&, mozilla::ComposerCommandsUpdater&, unsigned int) [editor/libeditor/HTMLEditor.cpp:412]
#14: nsEditingSession::SetupEditorOnWindow(nsPIDOMWindowOuter&) [editor/composer/nsEditingSession.cpp:405]
```

The initialization is required only for empty table cells and empty list items
and they are typically not used at initial document.  So, I think that it's fine
to stop normalizing white-spaces before succeeded to initialize `HTMLEditor`.

If this change causes a web-compat issue in the wild, let's make it run
asynchronously.

Differential Revision: https://phabricator.services.mozilla.com/D239473
---
 editor/libeditor/HTMLEditSubActionHandler.cpp |  3 +++
 editor/libeditor/HTMLEditor.cpp               | 13 +++++++++++--
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/editor/libeditor/HTMLEditSubActionHandler.cpp b/editor/libeditor/HTMLEditSubActionHandler.cpp
index 5cccc5e610f9..95790fe06792 100644
--- a/editor/libeditor/HTMLEditSubActionHandler.cpp
+++ b/editor/libeditor/HTMLEditSubActionHandler.cpp
@@ -180,6 +180,9 @@ nsresult HTMLEditor::InitEditorContentAndSelection() {
     return NS_OK;
   }
 
+  // FIXME: This is odd to update the DOM for making users can put caret in
+  // empty table cells and list items.  We should make it possible without
+  // the hacky <br>.
   rv = InsertBRElementToEmptyListItemsAndTableCellsInRange(
       RawRangeBoundary(bodyOrDocumentElement, 0u),
       RawRangeBoundary(bodyOrDocumentElement,
diff --git a/editor/libeditor/HTMLEditor.cpp b/editor/libeditor/HTMLEditor.cpp
index 9646db9f908d..c48d7b136413 100644
--- a/editor/libeditor/HTMLEditor.cpp
+++ b/editor/libeditor/HTMLEditor.cpp
@@ -4430,12 +4430,20 @@ Result<EditorDOMPoint, nsresult> HTMLEditor::PrepareToInsertLineBreak(
            EditorUtils::IsNewLinePreformatted(aContent);
   };
 
+  // If we're being initialized, we cannot normalize white-spaces because the
+  // normalizer may remove invisible `Text`, but it's not allowed during the
+  // initialization.
+  // FIXME: Anyway, we should not do this at initialization. This is required
+  // only for making users can put caret into empty table cells and list items.
+  const bool canNormalizeWhiteSpaces = mInitSucceeded;
+
   if (!aPointToInsert.IsInTextNode()) {
     if (NS_WARN_IF(
             !CanInsertLineBreak(*aPointToInsert.ContainerAs<nsIContent>()))) {
       return Err(NS_ERROR_FAILURE);
     }
-    if (!StaticPrefs::editor_white_space_normalization_blink_compatible()) {
+    if (!canNormalizeWhiteSpaces ||
+        !StaticPrefs::editor_white_space_normalization_blink_compatible()) {
       return aPointToInsert;
     }
     Result<EditorDOMPoint, nsresult> pointToInsertOrError =
@@ -4459,7 +4467,8 @@ Result<EditorDOMPoint, nsresult> HTMLEditor::PrepareToInsertLineBreak(
   }
 
   Result<EditorDOMPoint, nsresult> pointToInsertOrError =
-      StaticPrefs::editor_white_space_normalization_blink_compatible()
+      canNormalizeWhiteSpaces &&
+              StaticPrefs::editor_white_space_normalization_blink_compatible()
           ? WhiteSpaceVisibilityKeeper::NormalizeWhiteSpacesToSplitAt(
                 *this, aPointToInsert,
                 {WhiteSpaceVisibilityKeeper::NormalizeOption::