Program: 167689
Project: 167689
Buggy source:
public BatchEditLineHandler(){
  super("String_Node_Str");
  ln=new ArgumentWithValue(this,0,"String_Node_Str");
  ln.addCantAppearAfter(helpArg);
  ArgumentWithValue line=new ArgumentWithValue(this,new CommandLineCompleter(){
    @Override public int complete(    CommandContext ctx,    String buffer,    int cursor,    List<String> candidates){
      final String lnStr=ln.getValue(ctx.getParsedCommandLine());
      if (lnStr == null) {
        return -1;
      }
      final String originalLine=ctx.getParsedCommandLine().getOriginalLine();
      boolean skipWS;
      int wordCount;
      if (Character.isWhitespace(originalLine.charAt(0))) {
        skipWS=true;
        wordCount=0;
      }
 else {
        skipWS=false;
        wordCount=1;
      }
      int cmdStart=1;
      while (cmdStart < originalLine.length()) {
        if (skipWS) {
          if (!Character.isWhitespace(originalLine.charAt(cmdStart))) {
            skipWS=false;
            ++wordCount;
            if (wordCount == 3) {
              break;
            }
          }
        }
 else         if (Character.isWhitespace(originalLine.charAt(cmdStart))) {
          skipWS=true;
        }
        ++cmdStart;
      }
      final String cmd;
      if (wordCount == 2) {
        cmd="String_Node_Str";
      }
 else       if (wordCount != 3) {
        return -1;
      }
 else {
        cmd=originalLine.substring(cmdStart);
      }
      int cmdResult=ctx.getDefaultCommandCompleter().complete(ctx,cmd,cmd.length(),candidates);
      if (cmdResult < 0) {
        return cmdResult;
      }
      int escapeCorrection=0;
      int start=originalLine.length() - 1 - buffer.length();
      while (start - escapeCorrection >= 0) {
        final char ch=originalLine.charAt(start - escapeCorrection);
        if (Character.isWhitespace(ch) || ch == '=') {
          break;
        }
        ++escapeCorrection;
      }
      return buffer.length() + escapeCorrection - (cmd.length() - cmdResult);
    }
  }
,Integer.MAX_VALUE,"String_Node_Str"){
  }
;
  line.addRequiredPreceding(ln);
}

Fixed version (ground truth):
public BatchEditLineHandler(){
  super("String_Node_Str");
  ln=new ArgumentWithValue(this,0,"String_Node_Str");
  ln.addCantAppearAfter(helpArg);
  ArgumentWithValue line=new ArgumentWithValue(this,new CommandLineCompleter(){
    @Override public int complete(    CommandContext ctx,    String buffer,    int cursor,    List<String> candidates){
      final String lnStr=ln.getValue(ctx.getParsedCommandLine());
      if (lnStr == null) {
        return -1;
      }
      final String substitutedLine=ctx.getParsedCommandLine().getSubstitutedLine();
      boolean skipWS;
      int wordCount;
      if (Character.isWhitespace(substitutedLine.charAt(0))) {
        skipWS=true;
        wordCount=0;
      }
 else {
        skipWS=false;
        wordCount=1;
      }
      int cmdStart=1;
      while (cmdStart < substitutedLine.length()) {
        if (skipWS) {
          if (!Character.isWhitespace(substitutedLine.charAt(cmdStart))) {
            skipWS=false;
            ++wordCount;
            if (wordCount == 3) {
              break;
            }
          }
        }
 else         if (Character.isWhitespace(substitutedLine.charAt(cmdStart))) {
          skipWS=true;
        }
        ++cmdStart;
      }
      final String cmd;
      if (wordCount == 2) {
        cmd="String_Node_Str";
      }
 else       if (wordCount != 3) {
        return -1;
      }
 else {
        cmd=substitutedLine.substring(cmdStart);
      }
      int cmdResult=ctx.getDefaultCommandCompleter().complete(ctx,cmd,cmd.length(),candidates);
      if (cmdResult < 0) {
        return cmdResult;
      }
      int escapeCorrection=0;
      int start=substitutedLine.length() - 1 - buffer.length();
      while (start - escapeCorrection >= 0) {
        final char ch=substitutedLine.charAt(start - escapeCorrection);
        if (Character.isWhitespace(ch) || ch == '=') {
          break;
        }
        ++escapeCorrection;
      }
      return buffer.length() + escapeCorrection - (cmd.length() - cmdResult);
    }
  }
,Integer.MAX_VALUE,"String_Node_Str"){
  }
;
  line.addRequiredPreceding(ln);
}