Fix user mention regular expression and group replacement.

The regular expression used for user mentions used to work
only inside sentences. Also, since it tested for whitespace, the
whitespace would get replaced, too, which would join lines together.

Instead the new regex uses boundary matchers to match against
word boundaires. As these are not capturing only the actual user
mention can be captured and is then replaced. Also, this way the
regex can ignore punctuation like in "@jim, look at this."

Since Gibtlit now requires Java 7 we can use named capture groups.
This makes the use of a centrally defined regular expression much
safer. The (admittedly only) group to capture the user name is named
"user" and can be referenced by this name. By using the name instead
of a group number, the regex could be changed without the code using
it breaking because the group number changed.

A simple test is added for user mentions, which unfortunately
has to deal with the full markdown replacement, too.

Fixes #985

src/main/java/com/gitblit/Constants.java

@@ -67,7 +67,7 @@ public class Constants {
 	 * This regular expression is used when searching for "mentions" in tickets
 	 * (when someone writes @thisOtherUser)
 	 */
-	public static final String REGEX_TICKET_MENTION = "\\s@([^\\s]+)";
+	public static final String REGEX_TICKET_MENTION = "\\B@(?<user>[^\\s]+)\\b";
 
 	public static final String ZIP_PATH = "/zip/";
 

src/main/java/com/gitblit/models/TicketModel.java

@@ -778,7 +778,7 @@ public class TicketModel implements Serializable, Comparable<TicketModel> {
 				Pattern mentions = Pattern.compile(Constants.REGEX_TICKET_MENTION);
 				Matcher m = mentions.matcher(text);
 				while (m.find()) {
-					String username = m.group(1);
+					String username = m.group("user");
 					plusList(Field.mentions, username);
 				}
 			} catch (Exception e) {

src/main/java/com/gitblit/tickets/TicketNotifier.java

@@ -576,7 +576,7 @@ public class TicketNotifier {
 			Pattern p = Pattern.compile(Constants.REGEX_TICKET_MENTION);
 			Matcher m = p.matcher(lastChange.comment.text);
 			while (m.find()) {
-				String username = m.group();
+				String username = m.group("user");
 				ccs.add(username);
 			}
 		}

src/main/java/com/gitblit/utils/MarkdownUtils.java

@@ -138,7 +138,7 @@ public class MarkdownUtils {
 		String canonicalUrl = settings.getString(Keys.web.canonicalUrl, "https://localhost:8443");
 
 		// emphasize and link mentions
-		String mentionReplacement = String.format(" **[@$1](%1s/user/$1)**", canonicalUrl);
+		String mentionReplacement = String.format("**[@${user}](%1s/user/${user})**", canonicalUrl);
 		text = text.replaceAll(Constants.REGEX_TICKET_MENTION, mentionReplacement);
 
 		// link ticket refs

src/test/java/com/gitblit/tests/MarkdownUtilsTest.java

@@ -15,8 +15,14 @@
  */
 package com.gitblit.tests;
 
+import java.util.HashMap;
+import java.util.Map;
+
 import org.junit.Test;
 
+import com.gitblit.IStoredSettings;
+import com.gitblit.Keys;
+import com.gitblit.tests.mock.MemorySettings;
 import com.gitblit.utils.MarkdownUtils;
 
 public class MarkdownUtilsTest extends GitblitUnitTest {
@@ -39,4 +45,70 @@ public class MarkdownUtilsTest extends GitblitUnitTest {
 		assertEquals("<table><tr><td>&lt;test&gt;</td></tr></table>",
 				MarkdownUtils.transformMarkdown("<table><tr><td>&lt;test&gt;</td></tr></table>"));
 	}
-}
+
+
+	@Test
+	public void testUserMentions() {
+		IStoredSettings settings = getSettings();
+		String repositoryName = "test3";
+		String mentionHtml = "<strong><a href=\"http://localhost/user/%1$s\">@%1$s</a></strong>";
+
+		String input = "@j.doe";
+		String output = "<p>" + String.format(mentionHtml, "j.doe") + "</p>";
+		assertEquals(output, MarkdownUtils.transformGFM(settings, input, repositoryName));
+
+		input = " @j.doe";
+		output = "<p>" + String.format(mentionHtml, "j.doe") + "</p>";
+		assertEquals(output, MarkdownUtils.transformGFM(settings, input, repositoryName));
+
+		input = "@j.doe.";
+		output = "<p>" + String.format(mentionHtml, "j.doe") + ".</p>";
+		assertEquals(output, MarkdownUtils.transformGFM(settings, input, repositoryName));
+
+		input = "To @j.doe: ask @jim.beam!";
+		output = "<p>To " + String.format(mentionHtml, "j.doe")
+				+ ": ask " + String.format(mentionHtml, "jim.beam") + "!</p>";
+		assertEquals(output, MarkdownUtils.transformGFM(settings, input, repositoryName));
+
+		input =   "@sta.rt\n"
+				+ "\n"
+				+ "User mentions in tickets are broken.\n"
+				+ "So:\n"
+				+ "@mc_guyver can fix this.\n"
+				+ "@j.doe, can you test after the fix by @m+guyver?\n"
+				+ "Please review this, @jim.beam!\n"
+				+ "Was reported by @jill and @j!doe from jane@doe yesterday.\n"
+				+ "\n"
+				+ "@jack.daniels can vote for john@wayne.name hopefully.\n"
+				+ "@en.de";
+		output =  "<p>"	+ String.format(mentionHtml, "sta.rt") + "</p>"
+				+ "<p>"	+ "User mentions in tickets are broken.<br/>"
+				+ "So:<br/>"
+				+ String.format(mentionHtml, "mc_guyver") + " can fix this.<br/>"
+				+ String.format(mentionHtml, "j.doe") + ", can you test after the fix by " + String.format(mentionHtml, "m+guyver") + "?<br/>"
+				+ "Please review this, " + String.format(mentionHtml, "jim.beam") + "!<br/>"
+				+ "Was reported by " + String.format(mentionHtml, "jill")
+				+ " and " + String.format(mentionHtml, "j!doe")
+				+ " from <a href=\"mailto:&#106;a&#110;&#x65;&#x40;&#x64;&#x6f;&#101;\">&#106;a&#110;&#x65;&#x40;&#x64;&#x6f;&#101;</a> yesterday." 
+				+ "</p>"
+				+ "<p>" + String.format(mentionHtml, "jack.daniels") + " can vote for "
+				+ "<a href=\"mailto:&#x6a;&#x6f;h&#110;&#x40;&#119;a&#121;&#110;&#101;.&#110;a&#x6d;&#101;\">&#x6a;&#x6f;h&#110;&#x40;&#119;a&#121;&#110;&#101;.&#110;a&#x6d;&#101;</a> hopefully.<br/>"
+				+ String.format(mentionHtml, "en.de")
+				+ "</p>";
+		assertEquals(output, MarkdownUtils.transformGFM(settings, input, repositoryName));
+
+	}
+
+
+
+
+	private MemorySettings getSettings() {
+		Map<String, Object> backingMap = new HashMap<String, Object>();
+
+		backingMap.put(Keys.web.canonicalUrl, "http://localhost");
+		backingMap.put(Keys.web.shortCommitIdLength, "7");
+
+		MemorySettings ms = new MemorySettings(backingMap);
+		return ms;
+	}
+}