bundles/org.apache.jasper.glassfish/src/org/apache/jasper/compiler/JspReader.java
private boolean popFile() throws JasperException {

	// Is stack created ? (will happen if the Jsp file we're looking at is
	// missing.
	if (current == null || currFileId < 0) {
	    return false;
	}

	// Restore parser state:
	String fName = getFile(currFileId);
	currFileId = unregisterSourceFile(fName);
	if (currFileId < -1) {
	    err.jspError("jsp.error.file.not.registered", fName);
	}

	Mark previous = current.popStream();
	if (previous != null) {
	    master = current.baseDir;
	    current = previous;
	    return true;
	}
	// Note that although the current file is undefined here, "current"
	// is not set to null just for convience, for it maybe used to
	// set the current (undefined) position.
	return false;
    }
private boolean popFile() throws JasperException {

	// Is stack created ? (will happen if the Jsp file we're looking at is
	// missing.
	if (current == null || currFileId < 0) {
	    return false;
	}

	// Restore parser state:
	String fName = getFile(currFileId);
	currFileId = unregisterSourceFile(fName);
	if (currFileId < -1) {
	    err.jspError("jsp.error.file.not.registered", fName);
	}

	Mark previous = current.popStream();
	if (previous != null) {
	    master = current.baseDir;
	    current = previous;
	    return true;
	}
	// Note that although the current file is undefined here, "current"
	// is not set to null just for convience, for it maybe used to
	// set the current (undefined) position.
	return false;
    }
Pop a file from the file stack.  The field "current" is retored
to the value to point to the previous files, if any, and is set
to null otherwise.
@return true is there is a previous file on the stck.
false otherwise.