Bug 37197 Basepath for relative pathes in JAR-exporter
The basepath for the JAR-exporter is the eclipse-install-directory. I prefer it to be the root of the project (the description is saved in), so that relative pathes end inside the project. Now: <jardesc> <jar path="workspace/projectdir/jar.jar"/> Desired: <jardesc> <jar path="jar.jar"/> Reason: To make the jardesc-files portable for shared projects
org.eclipse.jdt.ui/ui/org/eclipse/jdt/ui/jarpackager/JarWriter.java
}
	}
	
	/**
	 * Checks if the JAR file can be overwritten.
	 * If the JAR package setting does not allow to overwrite the JAR
	 * then a dialog will ask the user again.
	 * 
	 * @param	parent	the parent for the dialog,
	 * 			or <code>null</code> if no dialog should be presented
	 * @return	<code>true</code> if it is OK to create the JAR
	 */
	protected boolean canCreateJar(Shell parent) {
		File file= fJarPackage.getJarLocation().toFile();
		if (file.exists()) {
			if (!file.canWrite())
				return false;
			if (fJarPackage.allowOverwrite())
				return true;
			return parent != null && JarPackagerUtil.askForOverwritePermission(parent, fJarPackage.getJarLocation().toOSString());
		}
					
		
		String path= file.getAbsolutePath();
		int separatorIndex = path.lastIndexOf(File.separator);
		if (separatorIndex == -1) 
			return true;
		File directory= new File(path.substring(0, separatorIndex));
		if (!directory.exists()) {
			if (JarPackagerUtil.askToCreateDirectory(parent, directory))