Bug 46805 prepare Compare for encoding support
I20031111 The Compare plugin only supports the global workspace encoding. It does not support encodings per file.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/compare/JavaCompareAction.java
if (ref instanceof IJavaElement) {
			IJavaElement parent= ((IJavaElement) ref).getParent();
			if (parent instanceof ISourceReference) {
				ISourceReference sr= (ISourceReference) parent;
				String parentContent= sr.getSource();
				if (parentContent != null) {
					ISourceRange parentRange= sr.getSourceRange();
					ISourceRange childRange= ref.getSourceRange();
					
					int start= childRange.getOffset() - parentRange.getOffset();
					int end= start + childRange.getLength();
					
					
					while (start > 0) {
						char c= parentContent.charAt(start-1);
						if (c == '\n' || c == '\r')
							break;
						start--;
					}
					
					return parentContent.substring(start, end);
				}
			}
		}
		
		return ref.getSource();
	}
}