Blink does not respect input.selectionStart and input.selectionEnd for some cases

Source/core/html/HTMLTextFormControlElement.cpp

Index: Source/core/html/HTMLTextFormControlElement.cpp
diff --git a/Source/core/html/HTMLTextFormControlElement.cpp b/Source/core/html/HTMLTextFormControlElement.cpp
index 0434728f24a557dcb6aa4a94af75ce08ceaccc60..b7af2c497189936fd728c10d8c1c9fd7b94bad4a 100644
--- a/Source/core/html/HTMLTextFormControlElement.cpp
+++ b/Source/core/html/HTMLTextFormControlElement.cpp
@@ -282,13 +282,21 @@ void HTMLTextFormControlElement::setSelectionRange(int start, int end, TextField
     if (!renderer() || !renderer()->isTextControl())
         return;
 
-    end = std::max(end, 0);
-    start = std::min(std::max(start, 0), end);
+    int textLength = innerEditorValue().length();
+    end = std::max(std::min(end, textLength), 0);
+    start = std::max(std::min(start, end), 0);
+    cacheSelection(start, end, direction);
+    bool isCaretSelection = start == end;
+    bool shouldSetSelection = document().focusedElement() == this || (!isCaretSelection && start < textLength);
+
+    if (!hasVisibleTextArea(renderer(), innerEditorElement()))
+        return;
+
+    LocalFrame* frame = document().frame();
 
-    if (!hasVisibleTextArea(renderer(), innerEditorElement())) {
-        cacheSelection(start, end, direction);
+    if (!frame || !shouldSetSelection)
         return;
-    }
+
     VisiblePosition startPosition = visiblePositionForIndex(start);
     VisiblePosition endPosition;
     if (start == end)
@@ -309,8 +317,7 @@ void HTMLTextFormControlElement::setSelectionRange(int start, int end, TextField
         newSelection = VisibleSelection(startPosition, endPosition);
     newSelection.setIsDirectional(direction != SelectionHasNoDirection);
 
-    if (LocalFrame* frame = document().frame())
-        frame->selection().setSelection(newSelection);
+    frame->selection().setSelection(newSelection);
 }
 
 VisiblePosition HTMLTextFormControlElement::visiblePositionForIndex(int index) const
@@ -342,7 +349,6 @@ int HTMLTextFormControlElement::selectionStart() const
         return 0;
     if (document().focusedElement() != this)
         return m_cachedSelectionStart;
-

[tkent, 2014/07/08 00:34:48]

nit: This blank line change is unnecessary.

[harpreet.sk, 2014/07/08 06:07:59]

Done.

     return computeSelectionStart();
 }
 
@@ -477,8 +483,8 @@ void HTMLTextFormControlElement::selectionChanged(bool userTriggered)
     if (!renderer() || !isTextFormControl())
         return;
 
-    // selectionStart() or selectionEnd() will return cached selection when this node doesn't have focus
-    cacheSelection(computeSelectionStart(), computeSelectionEnd(), computeSelectionDirection());
+    if (document().focusedElement() == this)
+        cacheSelection(computeSelectionStart(), computeSelectionEnd(), computeSelectionDirection());
 
     if (LocalFrame* frame = document().frame()) {
         if (frame->selection().isRange() && userTriggered)