use the url of the feed as the base url to resolve relative entry links when the declared link in the feed is relative

src/main/java/com/commafeed/backend/feeds/FeedParser.java

@@ -82,7 +82,7 @@ public class FeedParser {
 					continue;
 				}
 				entry.setGuid(FeedUtils.truncate(guid, 2048));
-				entry.setUrl(FeedUtils.truncate(FeedUtils.toAbsoluteUrl(item.getLink(), feed.getLink()), 2048));
+				entry.setUrl(FeedUtils.truncate(FeedUtils.toAbsoluteUrl(item.getLink(), feed.getLink(), feed.getUrlAfterRedirect()), 2048));
 				entry.setUpdated(validateDate(getEntryUpdateDate(item), true));
 
 				FeedEntryContent content = new FeedEntryContent();

src/main/java/com/commafeed/backend/feeds/FeedUtils.java

@@ -1,6 +1,8 @@
 package com.commafeed.backend.feeds;
 
 import java.io.StringReader;
+import java.net.MalformedURLException;
+import java.net.URL;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.Date;
@@ -15,6 +17,7 @@ import org.apache.commons.lang.ArrayUtils;
 import org.apache.commons.lang.StringUtils;
 import org.apache.commons.lang3.time.DateUtils;
 import org.apache.commons.math.stat.descriptive.SummaryStatistics;
+import org.apache.wicket.request.UrlUtils;
 import org.jsoup.Jsoup;
 import org.jsoup.nodes.Document;
 import org.jsoup.nodes.Document.OutputSettings;
@@ -389,17 +392,37 @@ public class FeedUtils {
 		return url;
 	}
 
-	public static String toAbsoluteUrl(String url, String baseUrl) {
+	/**
+	 * 
+	 * @param url
+	 *            the url of the entry
+	 * @param feedLink
+	 *            the url of the feed as described in the feed
+	 * @param feedUrl
+	 *            the url of the feed that we used to fetch the feed
+	 * @return an absolute url pointing to the entry
+	 */
+	public static String toAbsoluteUrl(String url, String feedLink, String feedUrl) {
 		url = StringUtils.trimToNull(StringUtils.normalizeSpace(url));
-		if (baseUrl == null || url == null || url.startsWith("http")) {
+		if (url == null || url.startsWith("http")) {
 			return url;
 		}
 
-		if (url.startsWith("/") == false) {
+		String baseUrl = (feedLink == null || UrlUtils.isRelative(feedLink)) ? feedUrl : feedLink;
-			url = "/" + url;
+
+		if (baseUrl == null) {
+			return url;
 		}
 
-		return baseUrl + url;
+		String result = null;
+		try {
+			result = new URL(new URL(baseUrl), url).toString();
+		} catch (MalformedURLException e) {
+			log.debug("could not parse url : " + e.getMessage(), e);
+			result = url;
+		}
+
+		return result;
 	}
 
 	public static String getFaviconUrl(FeedSubscription subscription, String publicUrl) {

src/test/java/com/commafeed/backend/feeds/FeedUtilsTest.java

@@ -22,7 +22,6 @@ public class FeedUtilsTest {
 		String urlc4 = "http://feeds.feedburner.com/Frandroid/";
 		String urlc5 = "http://feeds.feedburner.com/Frandroid?format=rss";
 
-		
 		String urld1 = "http://fivefilters.org/content-only/makefulltextfeed.php?url=http://feeds.feedburner.com/Frandroid";
 		String urld2 = "http://fivefilters.org/content-only/makefulltextfeed.php?url=http://feeds2.feedburner.com/Frandroid";
 
@@ -41,5 +40,17 @@ public class FeedUtilsTest {
 		Assert.assertNotEquals(FeedUtils.normalizeURL(urld1), FeedUtils.normalizeURL(urld2));
 
 	}
-}
 
+	@Test
+	public void testToAbsoluteUrl() {
+		String expected = "http://a.com/blog/entry/1";
+		Assert.assertEquals(expected, FeedUtils.toAbsoluteUrl("http://a.com/blog/entry/1", "http://a.com/feed/", "http://a.com/feed/"));
+		Assert.assertEquals(expected, FeedUtils.toAbsoluteUrl("http://a.com/blog/entry/1", "http://a.com/feed", "http://a.com/feed"));
+		Assert.assertEquals(expected, FeedUtils.toAbsoluteUrl("../blog/entry/1", "http://a.com/feed/", "http://a.com/feed/"));
+		Assert.assertEquals(expected, FeedUtils.toAbsoluteUrl("../blog/entry/1", "feed.xml", "http://a.com/feed/feed.xml"));
+
+		Assert.assertEquals("http://ergoemacs.org/emacs/elisp_all_about_lines.html",
+				FeedUtils.toAbsoluteUrl("elisp_all_about_lines.html", "blog.xml", "http://ergoemacs.org/emacs/blog.xml"));
+
+	}
+}