Modify a WordPress search results template to directly link to PDF files included in results (see Revisions for changes made)

gistfile1.php

<?php global $post; ?>
<!-- Start the Loop. -->
<?php if (have_posts()) : while (have_posts()) : the_post(); ?>
        <!--post Start-->
        <div id="post-<?php the_ID(); ?>" <?php post_class(); ?>>
            <?php
                // our default will be the post permalink
                $permalink = get_permalink();
                
                // the default excerpt will be the post excerpt
                $excerpt = get_the_excerpt();

                // check to see if the result is an attachment
                if( 'attachment' == get_post_type() ) {
                    // check to see if the result is a PDF
                    if( 'application/pdf' == get_post_mime_type( $post->ID ) ) {
                        // override the permalink
                        $permalink = wp_get_attachment_url( $post->ID );
                        // override the excerpt
                        $excerpt = get_post_meta( $post->ID, 'searchwp_content', true );
                        $excerpt_char_length = 250; // change this to be how many characters you want in the excerpt
                        $excerpt = substr( $excerpt, 0, $excerpt_char_length ) . '[...]';
                    }
                }
            ?>
            <h1 class="post_title"><a href="<?php echo $permalink; ?>" rel="bookmark" title="<?php printf(esc_attr__('Permalink to %s', 'andrina-lite'), the_title_attribute('echo=0')); ?>"><?php the_title(); ?></a></h1>
            <div class="post_content"><?php if (has_post_thumbnail()) { ?>
                    <a href="<?php echo $permalink; ?>">
                        <?php the_post_thumbnail('post_thumbnail', array('class' => 'postimg')); ?>
                    </a>
                <?php } else { ?>
                    <a href="<?php echo $permalink; ?>"><?php echo inkthemes_main_image(250, 170); ?></a>
                    <?php
                }
                ?>	
                <?php echo $excerpt; ?>
                <div class="clear"></div>
                <?php if (has_tag()) { ?>
                    <div class="tag">
                        <?php the_tags(__('Post Tagged with ', ', ', '')); ?>
                    </div>
                <?php } ?>
                <ul class="post_meta">
                    <li class="post_date"><?php the_date(); ?></li>
                    <li class="post_category"><span>/&nbsp;&nbsp;<?php _e('Category', 'andrina-lite'); ?></span>&nbsp;<?php the_category(', '); ?></li>
                </ul>
                <a class="read_more" href="<?php echo $permalink; ?>"><?php _e('Read More', 'andrina-lite'); ?></a> </div>
        </div>
        <!--post End-->
    <?php
    endwhile;
else:
    ?>
    <div class="post">
        <p>
    <?php _e('Sorry, no posts matched your criteria.', 'andrina-lite'); ?>
        </p>
    </div>
<?php endif; ?>
<!--End Loop-->