Fix setComposingText 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 0d88e0f740a014a088b732b6340f8ca8bef0e15e..1db29aa05f7b914a40c966144643b758c0d9040a 100644
--- a/third_party/WebKit/Source/core/editing/InputMethodController.cpp
+++ b/third_party/WebKit/Source/core/editing/InputMethodController.cpp
@@ -239,7 +239,7 @@ void InputMethodController::cancelCompositionIfSelectionIsInvalid()
     frame().chromeClient().didCancelCompositionOnSelectionChange();
 }
 
-void InputMethodController::setComposition(const String& text, const Vector<CompositionUnderline>& underlines, unsigned selectionStart, unsigned selectionEnd)
+void InputMethodController::setComposition(const String& text, const Vector<CompositionUnderline>& underlines, int selectionStart, int selectionEnd)
 {
     Editor::RevealSelectionScope revealSelectionScope(&editor());
 
@@ -332,9 +332,25 @@ void InputMethodController::setComposition(const String& text, const Vector<Comp
     if (baseNode->layoutObject())
         baseNode->layoutObject()->setShouldDoFullPaintInvalidation();
 
-    unsigned start = std::min(baseOffset + selectionStart, extentOffset);
-    unsigned end = std::min(std::max(start, baseOffset + selectionEnd), extentOffset);
-    Range* selectedRange = Range::create(baseNode->document(), baseNode, start, baseNode, end);
+    // In case of exceeding the left boundary.
+    int start = std::max(static_cast<int>(getSelectionOffsets().start()) + selectionStart, 0);
+    int end = std::max(static_cast<int>(getSelectionOffsets().start()) + selectionEnd, start);
+
+    Element* rootEditableElement = frame().selection().rootEditableElement();
+    if (!rootEditableElement)
+        return;
+
+    // In case of exceeding the right boundary.
+    const EphemeralRange startRange = PlainTextRange(0, start).createRange(*rootEditableElement);

[Changwan Ryu, 2016/05/09 12:52:23]

You can create only range to handle both:

const EphemeralRange range = PlainTextRange(start, end);

[yabinh, 2016/05/09 13:02:50]

If both number1 and number2 exceed the right boundary,
PlainTextRange::createRange(number1, number2) will return a default value, which
is [0,0]. So if we want to get the  right boundary, we should make sure number1
is within range at least. That's why we need to call it 2 times.

+    const EphemeralRange endRange = PlainTextRange(0, end).createRange(*rootEditableElement);
+
+    start = startRange.endPosition().computeOffsetInContainerNode();
+    Node* startNode = startRange.endPosition().computeContainerNode();
+
+    end = endRange.endPosition().computeOffsetInContainerNode();
+    Node* endNode = endRange.endPosition().computeContainerNode();
+
+    Range* selectedRange = Range::create(rootEditableElement->document(), startNode, start, endNode, end);
     frame().selection().setSelectedRange(selectedRange, TextAffinity::Downstream, SelectionDirectionalMode::NonDirectional, NotUserTriggered);
 
     if (underlines.isEmpty()) {