Reland: Fix setComposingText with empty text when newCursorPosition != 1

third_party/WebKit/Source/core/editing/InputMethodController.cpp

Index: third_party/WebKit/Source/core/editing/InputMethodController.cpp
diff --git a/third_party/WebKit/Source/core/editing/InputMethodController.cpp b/third_party/WebKit/Source/core/editing/InputMethodController.cpp
index 0bd3b86d91b2380d6a7380e89bc63feae01cc7e0..f5c91b1d36eba691b44fe78db2c1ec2ae16baa15 100644
--- a/third_party/WebKit/Source/core/editing/InputMethodController.cpp
+++ b/third_party/WebKit/Source/core/editing/InputMethodController.cpp
@@ -321,6 +321,10 @@ void InputMethodController::setComposition(const String& text, const Vector<Comp
     if (!target)
         return;
 
+    int selectionOffsetsStart = static_cast<int>(getSelectionOffsets().start());
+    int start = selectionOffsetsStart + selectionStart;
+    int end = selectionOffsetsStart + selectionEnd;
+
     // Dispatch an appropriate composition event to the focused node.
     // We check the composition status and choose an appropriate composition event since this
     // function is used for three purposes:
@@ -339,11 +343,13 @@ void InputMethodController::setComposition(const String& text, const Vector<Comp
     if (text.isEmpty()) {
         if (hasComposition()) {
             confirmComposition(emptyString());
+            setEditableSelectionOffsets(start, end);
             return;
         }
         // It's weird to call |setComposition()| with empty text outside composition, however some IME
         // (e.g. Japanese IBus-Anthy) did this, so we simply delete selection without sending extra events.
         TypingCommand::deleteSelection(*frame().document(), TypingCommand::PreventSpellChecking);
+        setEditableSelectionOffsets(start, end);
         return;
     }
 
@@ -390,31 +396,7 @@ void InputMethodController::setComposition(const String& text, const Vector<Comp
     if (baseNode->layoutObject())
         baseNode->layoutObject()->setShouldDoFullPaintInvalidation();
 
-    // In case of exceeding the left boundary.
-    int selectionOffsetsStart = static_cast<int>(getSelectionOffsets().start());
-    int start = std::max(selectionOffsetsStart + selectionStart, 0);
-    int end = std::max(selectionOffsetsStart + selectionEnd, start);
-
-    Element* rootEditableElement = frame().selection().rootEditableElement();
-    if (!rootEditableElement)
-        return;
-
-    // In case of exceeding the right boundary.
-    // If both |value1| and |value2| exceed right boundary,
-    // PlainTextRange(value1, value2)::createRange() will return a default
-    // value, which is [0,0]. In order to get the correct Position in that case,
-    // we should make sure |value1| is within range at least.
-    const EphemeralRange& startRange = PlainTextRange(0, start).createRange(*rootEditableElement);
-    const EphemeralRange& endRange = PlainTextRange(0, end).createRange(*rootEditableElement);
-
-    // TODO(yabinh): There should be a better way to create |startPosition| and
-    // |endPosition|. But for now, since we can't get |anchorNode| and |offset|,
-    // we can't create the 2 Position objects directly. So we use
-    // PlainTextRange::createRange as a workaround.
-    const Position& startPosition = startRange.endPosition();
-    const Position& endPosition = endRange.endPosition();
-    const EphemeralRange selectedRange(startPosition, endPosition);
-    frame().selection().setSelectedRange(selectedRange, TextAffinity::Downstream, SelectionDirectionalMode::NonDirectional, NotUserTriggered);
+    setEditableSelectionOffsets(start, end);
 
     if (underlines.isEmpty()) {
         frame().document()->markers().addCompositionMarker(m_compositionRange->startPosition(), m_compositionRange->endPosition(), Color::black, false, LayoutTheme::theme().platformDefaultCompositionBackgroundColor());
@@ -508,11 +490,42 @@ bool InputMethodController::setSelectionOffsets(const PlainTextRange& selectionO
     return frame().selection().setSelectedRange(range, VP_DEFAULT_AFFINITY, SelectionDirectionalMode::NonDirectional, FrameSelection::CloseTyping);
 }
 
-bool InputMethodController::setEditableSelectionOffsets(const PlainTextRange& selectionOffsets)
+bool InputMethodController::setEditableSelectionOffsets(int start, int end)
 {
     if (!editor().canEdit())
         return false;
-    return setSelectionOffsets(selectionOffsets);
+
+    Element* rootEditableElement = frame().selection().rootEditableElement();
+    if (!rootEditableElement)
+        return false;
+
+    // In case of exceeding the left boundary.
+    start = std::max(start, 0);
+    end = std::max(end, start);
+
+    // In case of exceeding the right boundary.
+    // If both |value1| and |value2| exceed right boundary,
+    // PlainTextRange(value1, value2)::createRange() will return a default
+    // value, which is [0,0]. In order to get the correct Position in that case,
+    // we should make sure |value1| is within range at least.
+    const EphemeralRange& startRange = PlainTextRange(0, start).createRange(*rootEditableElement);
+    if (startRange.isNull())
+        return false;
+    const EphemeralRange& endRange = PlainTextRange(0, end).createRange(*rootEditableElement);
+    if (endRange.isNull())
+        return false;
+
+    // TODO(yabinh): There should be a better way to create |startPosition| and
+    // |endPosition|. But for now, since we can't get |anchorNode| and |offset|,
+    // we can't create the 2 Position objects directly. So we use
+    // PlainTextRange::createRange as a workaround.
+    const Position& startPosition = startRange.endPosition();
+    const Position& endPosition = endRange.endPosition();
+    const EphemeralRange& range = EphemeralRange(startPosition, endPosition);
+    if (range.isNull())
+        return false;
+
+    return frame().selection().setSelectedRange(range, VP_DEFAULT_AFFINITY, SelectionDirectionalMode::NonDirectional, FrameSelection::CloseTyping);
 }
 
 void InputMethodController::extendSelectionAndDelete(int before, int after)