Program: 7842
Project: 7842
Buggy source:
private void checkPage(){
  String projectName=projectText.getText();
  setErrorMessage(null);
  try {
    if (!myDirectory.exists()) {
      setErrorMessage(NLS.bind(UIText.GitCreateGeneralProjectPage_DirNotExistMessage,myDirectory.getPath()));
      return;
    }
    if (!myDirectory.isDirectory()) {
      setErrorMessage(NLS.bind(UIText.GitCreateGeneralProjectPage_FileNotDirMessage,myDirectory.getPath()));
      return;
    }
    if (myDirectory.list(new FilenameFilter(){
      public boolean accept(      File dir,      String name){
        if (name.equals("String_Node_Str"))         return true;
        return false;
      }
    }
).length > 0) {
      setErrorMessage(NLS.bind(UIText.GitCreateGeneralProjectPage_FileExistsInDirMessage,"String_Node_Str",myDirectory.getPath()));
      return;
    }
    if (projectName.length() == 0) {
      setErrorMessage(UIText.GitCreateGeneralProjectPage_EnterProjectNameMessage);
      return;
    }
    IStatus result=ResourcesPlugin.getWorkspace().validateName(projectName,IResource.PROJECT);
    if (!result.isOK()) {
      setErrorMessage(result.getMessage());
      return;
    }
    if (isProjectInWorkspace(projectName)) {
      setErrorMessage(NLS.bind(UIText.GitCreateGeneralProjectPage_PorjectAlreadyExistsMessage,projectName));
      return;
    }
    IProject newProject=ResourcesPlugin.getWorkspace().getRoot().getProject(projectName);
    IStatus locationResult=ResourcesPlugin.getWorkspace().validateProjectLocation(newProject,new Path(myDirectory.getPath()));
    if (!locationResult.isOK()) {
      setErrorMessage(locationResult.getMessage());
      return;
    }
  }
  finally {
    setPageComplete(getErrorMessage() == null);
  }
}

Fixed version (ground truth):
private void checkPage(){
  String projectName=projectText.getText();
  setErrorMessage(null);
  try {
    if (!myDirectory.exists()) {
      setErrorMessage(NLS.bind(UIText.GitCreateGeneralProjectPage_DirNotExistMessage,myDirectory.getPath()));
      return;
    }
    if (!myDirectory.isDirectory()) {
      setErrorMessage(NLS.bind(UIText.GitCreateGeneralProjectPage_FileNotDirMessage,myDirectory.getPath()));
      return;
    }
    if (myDirectory.list(new FilenameFilter(){
      public boolean accept(      File dir,      String name){
        if (name.equals("String_Node_Str"))         return true;
        return false;
      }
    }
).length > 0) {
      setErrorMessage(NLS.bind(UIText.GitCreateGeneralProjectPage_FileExistsInDirMessage,"String_Node_Str",myDirectory.getPath()));
      return;
    }
    if (projectName.length() == 0) {
      setErrorMessage(UIText.GitCreateGeneralProjectPage_EnterProjectNameMessage);
      return;
    }
    IStatus result=ResourcesPlugin.getWorkspace().validateName(projectName,IResource.PROJECT);
    if (!result.isOK()) {
      setErrorMessage(result.getMessage());
      return;
    }
    if (isProjectInWorkspace(projectName)) {
      setErrorMessage(NLS.bind(UIText.GitCreateGeneralProjectPage_PorjectAlreadyExistsMessage,projectName));
      return;
    }
    if (!defaultLocation) {
      IProject newProject=ResourcesPlugin.getWorkspace().getRoot().getProject(projectName);
      IStatus locationResult=ResourcesPlugin.getWorkspace().validateProjectLocation(newProject,new Path(myDirectory.getPath()));
      if (!locationResult.isOK()) {
        setErrorMessage(locationResult.getMessage());
        return;
      }
    }
  }
  finally {
    setPageComplete(getErrorMessage() == null);
  }
}