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
fJarOutputStream= new JarOutputStream(new FileOutputStream(fJarPackage.getJarLocation().toOSString()), manifest);
			} else
				fJarOutputStream= new JarOutputStream(new FileOutputStream(fJarPackage.getJarLocation().toOSString()));
			String comment= jarPackage.getComment();
			if (comment != null)
				fJarOutputStream.setComment(comment);
		} catch (IOException ex) {
			throw JarPackagerUtil.createCoreException(ex.getLocalizedMessage(), ex);
		}
	}
	
	/**
	 * Closes the archive and does all required cleanup.
	 *
	 * @throws	CoreException	to signal any other unusal termination.
	 * 								This can also be used to return information
	 * 								in the status object.
	 */
	public void close() throws CoreException {
		if (fJarOutputStream != null)
			try {
				fJarOutputStream.close();
				registerInWorkspaceIfNeeded();
			} catch (IOException ex) {
				throw JarPackagerUtil.createCoreException(ex.getLocalizedMessage(), ex);
			}
	}
	
	/**
	 * Writes the passed resource to the current archive.