Program: 112204
Project: 112204
Buggy source:
private boolean checkCode(List<ValidationMessage> errors,Element element,String path,String code,String system,String display) throws TerminologyServiceException {
  long t=System.nanoTime();
  boolean ss=context.supportsSystem(system);
  txTime=txTime + (System.nanoTime() - t);
  if (ss) {
    t=System.nanoTime();
    ValidationResult s=context.validateCode(system,code,display);
    txTime=txTime + (System.nanoTime() - t);
    if (s == null)     return true;
    if (s.isOk()) {
      if (s.getMessage() != null)       warning(errors,IssueType.CODEINVALID,element.line(),element.col(),path,s == null,s.getMessage());
      return true;
    }
    if (s.getSeverity() == IssueSeverity.INFORMATION)     hint(errors,IssueType.CODEINVALID,element.line(),element.col(),path,s == null,s.getMessage());
 else     if (s.getSeverity() == IssueSeverity.WARNING)     warning(errors,IssueType.CODEINVALID,element.line(),element.col(),path,s == null,s.getMessage());
 else     return rule(errors,IssueType.CODEINVALID,element.line(),element.col(),path,s == null,s.getMessage());
    return true;
  }
 else   if (system.startsWith("String_Node_Str")) {
    if (system.equals("String_Node_Str"))     return true;
 else {
      CodeSystem cs=getCodeSystem(system);
      if (warning(errors,IssueType.CODEINVALID,element.line(),element.col(),path,cs != null,"String_Node_Str" + system)) {
        ConceptDefinitionComponent def=getCodeDefinition(cs,code);
        if (warning(errors,IssueType.CODEINVALID,element.line(),element.col(),path,def != null,"String_Node_Str" + system + "String_Node_Str"+ code+ "String_Node_Str"))         return warning(errors,IssueType.CODEINVALID,element.line(),element.col(),path,display == null || display.equals(def.getDisplay()),"String_Node_Str" + def.getDisplay() + "String_Node_Str");
      }
      return false;
    }
  }
 else   if (context.isNoTerminologyServer() && Utilities.existsInList(system,"String_Node_Str","String_Node_Str","String_Node_Str","String_Node_Str")) {
    return true;
  }
 else   if (startsWithButIsNot(system,"String_Node_Str","String_Node_Str","String_Node_Str","String_Node_Str")) {
    rule(errors,IssueType.CODEINVALID,element.line(),element.col(),path,false,"String_Node_Str" + system);
    return false;
  }
 else {
    try {
      if (context.fetchResourceWithException(ValueSet.class,system) != null) {
        rule(errors,IssueType.CODEINVALID,element.line(),element.col(),path,false,"String_Node_Str" + system + "String_Node_Str");
        return false;
      }
 else       return true;
    }
 catch (    Exception e) {
      return true;
    }
  }
}

Fixed version (ground truth):
private boolean checkCode(List<ValidationMessage> errors,Element element,String path,String code,String system,String display) throws TerminologyServiceException {
  long t=System.nanoTime();
  boolean ss=context.supportsSystem(system);
  txTime=txTime + (System.nanoTime() - t);
  if (ss) {
    t=System.nanoTime();
    ValidationResult s=context.validateCode(system,code,display);
    txTime=txTime + (System.nanoTime() - t);
    if (s == null)     return true;
    if (s.isOk()) {
      if (s.getMessage() != null)       warning(errors,IssueType.CODEINVALID,element.line(),element.col(),path,s == null,s.getMessage());
      return true;
    }
    if (s.getSeverity() == IssueSeverity.INFORMATION)     hint(errors,IssueType.CODEINVALID,element.line(),element.col(),path,s == null,s.getMessage());
 else     if (s.getSeverity() == IssueSeverity.WARNING)     warning(errors,IssueType.CODEINVALID,element.line(),element.col(),path,s == null,s.getMessage());
 else     return rule(errors,IssueType.CODEINVALID,element.line(),element.col(),path,s == null,s.getMessage());
    return true;
  }
 else   if (system.startsWith("String_Node_Str")) {
    if (system.equals("String_Node_Str"))     return true;
 else {
      CodeSystem cs=getCodeSystem(system);
      if (warning(errors,IssueType.CODEINVALID,element.line(),element.col(),path,cs != null,"String_Node_Str" + system)) {
        ConceptDefinitionComponent def=getCodeDefinition(cs,code);
        if (warning(errors,IssueType.CODEINVALID,element.line(),element.col(),path,def != null,"String_Node_Str" + system + "String_Node_Str"+ code+ "String_Node_Str"))         return warning(errors,IssueType.CODEINVALID,element.line(),element.col(),path,display == null || display.equals(def.getDisplay()),"String_Node_Str" + def.getDisplay() + "String_Node_Str");
      }
      return false;
    }
  }
 else   if (context.isNoTerminologyServer() && Utilities.existsInList(system,"String_Node_Str","String_Node_Str","String_Node_Str","String_Node_Str")) {
    return true;
  }
 else   if (startsWithButIsNot(system,"String_Node_Str","String_Node_Str","String_Node_Str","String_Node_Str")) {
    rule(errors,IssueType.CODEINVALID,element.line(),element.col(),path,false,"String_Node_Str" + system);
    return false;
  }
 else {
    try {
      if (context.fetchResourceWithException(ValueSet.class,system) != null) {
        rule(errors,IssueType.CODEINVALID,element.line(),element.col(),path,false,"String_Node_Str" + system + "String_Node_Str");
      }
      return true;
    }
 catch (    Exception e) {
      return true;
    }
  }
}