Block empty space selection

Source/core/editing/VisibleUnits.cpp

Index: Source/core/editing/VisibleUnits.cpp
diff --git a/Source/core/editing/VisibleUnits.cpp b/Source/core/editing/VisibleUnits.cpp
index 9ffa0c86b26111f990102052a61108d09d4f7224..adcbe0892f53355e63542650b1790b20b36b964b 100644
--- a/Source/core/editing/VisibleUnits.cpp
+++ b/Source/core/editing/VisibleUnits.cpp
@@ -766,6 +766,38 @@ static VisiblePosition startOfLine(const VisiblePosition& c, LineEndpointComputa
     return c.honorEditingBoundaryAtOrBefore(visPos);
 }
 
+bool isStartOfWordASpace(const VisiblePosition& visiblePosition)
+{
+    if (visiblePosition.isNull())
+        return false;
+
+    Position position = visiblePosition.deepEquivalent();
+    Node* node = position.anchorNode();
+    Document& document = node->document();
+
+    if (!document.documentElement())
+        return false;
+
+    Node* boundary = node->enclosingBlockFlowElement();
+    if (!boundary)
+        return false;
+
+    RefPtr<Range> searchRange(document.createRange());
+    Position start(position.parentAnchoredEquivalent());
+    TrackExceptionState exceptionState;
+
+    searchRange->selectNodeContents(boundary, exceptionState);
+    if (exceptionState.hadException())
+        return false;
+
+    searchRange->setStart(start.anchorNode(), start.deprecatedEditingOffset(), exceptionState);
+    if (exceptionState.hadException())
+        return false;
+
+    TextIterator it(searchRange.get(), TextIteratorEmitsCharactersBetweenAllVisiblePositions);
+    return it.length() ? isASCIISpace(it.characterAt(0)) : false;
+}
+
 // FIXME: Rename this function to reflect the fact it ignores bidi levels.
 VisiblePosition startOfLine(const VisiblePosition& currentPosition)
 {