Program: 91236
Project: 91236
Buggy source:
/** 
 * Expresses <code>other</code> as a relative file path from <code>base</code> <p> For example, if called with the two following paths : <pre> <code>base = "c:\\Users\\jdoe\\eclipse\\git\\project"</code> <code>other = "c:\\Users\\jdoe\\eclipse\\git\\another_project\\pom.xml"</code> </pre> This will return "..\\another_project\\pom.xml". </p> <p> <b>Note</b> that this will return the empty String if <code>base</code> and <code>other</code> are equal. </p>
 * @param base The path against which <code>other</code> should be relativized. This will be assumed to denote the path to a folder and not a file.
 * @param other The path that will be made relative to <code>base</code>.
 * @param dirSeparator A string that separates components of the path. In practice, this is "/" or "\\".
 * @param caseSensitive Whether to consider differently-cased directory names as distinct
 * @return A relative path that, when resolved against <code>base</code>,will yield the original <code>other</code>.
 * @since 4.8
 */
public static String relativizePath(String base,String other,String dirSeparator,boolean caseSensitive){
  if (base.equals(other))   return "String_Node_Str";
  final String[] baseSegments=base.split(Pattern.quote(dirSeparator));
  final String[] otherSegments=other.split(Pattern.quote(dirSeparator));
  int commonPrefix=0;
  while (commonPrefix < baseSegments.length && commonPrefix < otherSegments.length) {
    if (caseSensitive && baseSegments[commonPrefix].equals(otherSegments[commonPrefix]))     commonPrefix++;
 else     if (!caseSensitive && baseSegments[commonPrefix].equalsIgnoreCase(otherSegments[commonPrefix]))     commonPrefix++;
 else     break;
  }
  final StringBuilder builder=new StringBuilder();
  for (int i=commonPrefix; i < baseSegments.length; i++)   builder.append("String_Node_Str").append(dirSeparator);
  for (int i=commonPrefix; i < otherSegments.length; i++) {
    builder.append(otherSegments[i]);
    if (i < otherSegments.length - 1)     builder.append(dirSeparator);
  }
  return builder.toString();
}

Fixed version (ground truth):
/** 
 * Expresses <code>other</code> as a relative file path from <code>base</code> <p> For example, if called with the two following paths : <pre> <code>base = "c:\\Users\\jdoe\\eclipse\\git\\project"</code> <code>other = "c:\\Users\\jdoe\\eclipse\\git\\another_project\\pom.xml"</code> </pre> This will return "..\\another_project\\pom.xml". <p> <b>Note</b> that this will return the empty String if <code>base</code> and <code>other</code> are equal. </p>
 * @param base The path against which <code>other</code> should be relativized. This will be assumed to denote the path to a folder and not a file.
 * @param other The path that will be made relative to <code>base</code>.
 * @param dirSeparator A string that separates components of the path. In practice, this is "/" or "\\".
 * @param caseSensitive Whether to consider differently-cased directory names as distinct
 * @return A relative path that, when resolved against <code>base</code>,will yield the original <code>other</code>.
 * @since 4.8
 */
public static String relativizePath(String base,String other,String dirSeparator,boolean caseSensitive){
  if (base.equals(other))   return "String_Node_Str";
  final String[] baseSegments=base.split(Pattern.quote(dirSeparator));
  final String[] otherSegments=other.split(Pattern.quote(dirSeparator));
  int commonPrefix=0;
  while (commonPrefix < baseSegments.length && commonPrefix < otherSegments.length) {
    if (caseSensitive && baseSegments[commonPrefix].equals(otherSegments[commonPrefix]))     commonPrefix++;
 else     if (!caseSensitive && baseSegments[commonPrefix].equalsIgnoreCase(otherSegments[commonPrefix]))     commonPrefix++;
 else     break;
  }
  final StringBuilder builder=new StringBuilder();
  for (int i=commonPrefix; i < baseSegments.length; i++)   builder.append("String_Node_Str").append(dirSeparator);
  for (int i=commonPrefix; i < otherSegments.length; i++) {
    builder.append(otherSegments[i]);
    if (i < otherSegments.length - 1)     builder.append(dirSeparator);
  }
  return builder.toString();
}