From 3ab3b25fad54d5f251a329fd23c8a1e60e14a368 Mon Sep 17 00:00:00 2001
From: Ehsan Akhgari <ehsan@mozilla.com>
Date: Wed, 9 Aug 2017 19:17:22 -0400
Subject: [PATCH] Bug 1388917 - Fix moving of SelectionState in
 PlaceholderTransaction's constructor; r=masayuki

---
 editor/libeditor/EditorBase.cpp             | 1 +
 editor/libeditor/PlaceholderTransaction.cpp | 5 ++++-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/editor/libeditor/EditorBase.cpp b/editor/libeditor/EditorBase.cpp
index 88372a78c50e..c0ff3142f81c 100644
--- a/editor/libeditor/EditorBase.cpp
+++ b/editor/libeditor/EditorBase.cpp
@@ -677,6 +677,7 @@ EditorBase::DoTransaction(Selection* aSelection, nsITransaction* aTxn)
   if (mPlaceholderBatch && !mPlaceholderTransaction) {
     mPlaceholderTransaction =
       new PlaceholderTransaction(*this, mPlaceholderName, Move(mSelState));
+    MOZ_ASSERT(mSelState.isNothing());
 
     // We will recurse, but will not hit this case in the nested call
     DoTransaction(mPlaceholderTransaction);
diff --git a/editor/libeditor/PlaceholderTransaction.cpp b/editor/libeditor/PlaceholderTransaction.cpp
index 8f1fb812d30a..1b9ac6bbcfd3 100644
--- a/editor/libeditor/PlaceholderTransaction.cpp
+++ b/editor/libeditor/PlaceholderTransaction.cpp
@@ -24,9 +24,12 @@ PlaceholderTransaction::PlaceholderTransaction(
   , mForwarding(nullptr)
   , mCompositionTransaction(nullptr)
   , mCommitted(false)
-  , mStartSel(Move(*aSelState))
   , mEditorBase(&aEditorBase)
 {
+  // Make sure to move aSelState into a local variable to null out the original
+  // Maybe<SelectionState> variable.
+  Maybe<SelectionState> selState(Move(aSelState));
+  mStartSel = *selState;
   mName = aName;
 }