[InputEvent] Support |deleteByDrag|, |insertFromDrop| and fire in sequential order

third_party/WebKit/Source/core/editing/commands/DeleteSelectionCommand.cpp

Index: third_party/WebKit/Source/core/editing/commands/DeleteSelectionCommand.cpp
diff --git a/third_party/WebKit/Source/core/editing/commands/DeleteSelectionCommand.cpp b/third_party/WebKit/Source/core/editing/commands/DeleteSelectionCommand.cpp
index 75b424fa928737c228012284b845b1c2780ce75b..b7ef67cf9eac676da172afd3f0cd56853a371435 100644
--- a/third_party/WebKit/Source/core/editing/commands/DeleteSelectionCommand.cpp
+++ b/third_party/WebKit/Source/core/editing/commands/DeleteSelectionCommand.cpp
@@ -63,7 +63,7 @@ static bool isTableRowEmpty(Node* row)
     return true;
 }
 
-DeleteSelectionCommand::DeleteSelectionCommand(Document& document, bool smartDelete, bool mergeBlocksAfterDelete, bool expandForSpecialElements, bool sanitizeMarkup, InputEvent::InputType inputType)
+DeleteSelectionCommand::DeleteSelectionCommand(Document& document, bool smartDelete, bool mergeBlocksAfterDelete, bool expandForSpecialElements, bool sanitizeMarkup, InputEvent::InputType inputType, const Position& referenceMovePosition)
     : CompositeEditCommand(document)
     , m_hasSelectionToDelete(false)
     , m_smartDelete(smartDelete)
@@ -74,6 +74,7 @@ DeleteSelectionCommand::DeleteSelectionCommand(Document& document, bool smartDel
     , m_startsAtEmptyLine(false)
     , m_sanitizeMarkup(sanitizeMarkup)
     , m_inputType(inputType)
+    , m_referenceMovePosition(referenceMovePosition)
     , m_startBlock(nullptr)
     , m_endBlock(nullptr)
     , m_typingStyle(nullptr)
@@ -805,6 +806,7 @@ void DeleteSelectionCommand::clearTransientState()
     m_endingPosition = Position();
     m_leadingWhitespace = Position();
     m_trailingWhitespace = Position();
+    m_referenceMovePosition = Position();
 }
 
 // This method removes div elements with no attributes that have only one child or no children at all.
@@ -838,6 +840,19 @@ void DeleteSelectionCommand::doApply(EditingState* editingState)
     if (!m_selectionToDelete.isNonOrphanedRange() || !m_selectionToDelete.isContentEditable())
         return;
 
+    if (!m_referenceMovePosition.isNull()) {

[yosin_UTC9, 2016/09/28 04:19:03]

nit: s/!m_referenceMovePosition.isNull()/m_referenceMovePosition.isNotNull()/

[chongz, 2016/09/29 02:36:22]

Done.

+        // Update the position otherwise it may become invalid after the selection is deleted.

[yosin_UTC9, 2016/09/28 04:19:03]

Could you utilize |RelocatablePosition|?

[chongz, 2016/09/29 02:36:22]

Done.

+        Position selectionEnd = endingSelection().end();
+        if (m_referenceMovePosition.isOffsetInAnchor() && selectionEnd.isOffsetInAnchor()
+            && selectionEnd.computeContainerNode() == m_referenceMovePosition.computeContainerNode() && selectionEnd.offsetInContainerNode() < m_referenceMovePosition.offsetInContainerNode()) {
+            m_referenceMovePosition = Position(m_referenceMovePosition.computeContainerNode(), m_referenceMovePosition.offsetInContainerNode() - selectionEnd.offsetInContainerNode());
+
+            Position selectionStart = endingSelection().start();
+            if (selectionStart.isOffsetInAnchor() && selectionStart.computeContainerNode() == m_referenceMovePosition.computeContainerNode())
+                m_referenceMovePosition = Position(m_referenceMovePosition.computeContainerNode(), m_referenceMovePosition.offsetInContainerNode() + selectionStart.offsetInContainerNode());
+        }
+    }
+
     // save this to later make the selection with
     TextAffinity affinity = m_selectionToDelete.affinity();
 
@@ -928,6 +943,22 @@ void DeleteSelectionCommand::doApply(EditingState* editingState)
     calculateTypingStyleAfterDelete();
 
     setEndingSelection(VisibleSelection(m_endingPosition, affinity, endingSelection().isDirectional()));
+
+    // This deletion command is part or a move operation.
+    if (!m_referenceMovePosition.isNull()) {
+        // If the node for the destination has been removed as a result of the deletion,
+        // set the destination to the ending point after the deletion.
+        // Fixes: <rdar://problem/3910425> REGRESSION (Mail): Crash in ReplaceSelectionCommand;
+        //        selection is empty, leading to null deref
+        if (!m_referenceMovePosition.isConnected())
+            m_referenceMovePosition = endingSelection().start();
+
+        // Move selection shouldn't left empty <li> block.
+        cleanupAfterDeletion(editingState, createVisiblePositionDeprecated(m_referenceMovePosition));
+        if (editingState->isAborted())
+            return;
+    }
+
     clearTransientState();
 }
 
@@ -957,6 +988,7 @@ DEFINE_TRACE(DeleteSelectionCommand)
     visitor->trace(m_endingPosition);
     visitor->trace(m_leadingWhitespace);
     visitor->trace(m_trailingWhitespace);
+    visitor->trace(m_referenceMovePosition);
     visitor->trace(m_startBlock);
     visitor->trace(m_endBlock);
     visitor->trace(m_typingStyle);