Revert of 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 e36cea49358ce24b90a500afbec5b97eb29f8242..fd9f11c877fc25da37f18aca218068bf7c11f140 100644
--- a/third_party/WebKit/Source/core/editing/InputMethodController.cpp
+++ b/third_party/WebKit/Source/core/editing/InputMethodController.cpp
@@ -321,11 +321,6 @@
     if (!target)
         return;
 
-    int selectionOffsetsStart = static_cast<int>(getSelectionOffsets().start());
-    int start = selectionOffsetsStart + selectionStart;
-    int end = selectionOffsetsStart + selectionEnd;
-    PlainTextRange selectedRange = createRangeForSelection(start, end, text.length());
-
     // 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:
@@ -344,13 +339,11 @@
     if (text.isEmpty()) {
         if (hasComposition()) {
             confirmComposition(emptyString());
-        } else {
-            // 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);
+            return;
         }
-
-        setEditableSelectionOffsets(selectedRange);
+        // 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);
         return;
     }
 
@@ -401,7 +394,31 @@
     if (baseNode->layoutObject())
         baseNode->layoutObject()->setShouldDoFullPaintInvalidation();
 
-    setEditableSelectionOffsets(selectedRange);
+    // 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);
 
     if (underlines.isEmpty()) {
         frame().document()->markers().addCompositionMarker(m_compositionRange->startPosition(), m_compositionRange->endPosition(), Color::black, false, LayoutTheme::theme().platformDefaultCompositionBackgroundColor());
@@ -508,38 +525,6 @@
     if (!editor().canEdit())
         return false;
     return setSelectionOffsets(selectionOffsets);
-}
-
-PlainTextRange InputMethodController::createRangeForSelection(int start, int end, size_t textLength) const
-{
-    // In case of exceeding the left boundary.
-    start = std::max(start, 0);
-    end = std::max(end, start);
-
-    // In case of exceeding the right boundary.
-    Element* rootEditableElement = frame().selection().rootEditableElement();
-    if (!rootEditableElement)
-        return PlainTextRange();
-    const EphemeralRange& range = EphemeralRange::rangeOfContents(*rootEditableElement);
-    if (range.isNull())
-        return PlainTextRange();
-
-    const TextIteratorBehaviorFlags behaviorFlags = TextIteratorEmitsObjectReplacementCharacter | TextIteratorEmitsCharactersBetweenAllVisiblePositions;
-    TextIterator it(range.startPosition(), range.endPosition(), behaviorFlags);
-
-    int rightBoundary = 0;
-    for (; !it.atEnd(); it.advance())
-        rightBoundary += it.length();
-
-    if (hasComposition())
-        rightBoundary -= compositionRange()->text().length();
-
-    rightBoundary += textLength;
-
-    start = std::min(start, rightBoundary);
-    end = std::min(end, rightBoundary);
-
-    return PlainTextRange(start, end);
 }
 
 void InputMethodController::extendSelectionAndDelete(int before, int after)