[FIXED JENKINS-11948] report all the causes, not just one.

src/main/java/hudson/plugins/active_directory/ActiveDirectoryUnixAuthenticationProvider.java

@@ -58,22 +58,24 @@ public ActiveDirectoryUnixAuthenticationProvider(ActiveDirectorySecurityRealm re
 
     protected UserDetails retrieveUser(String username, UsernamePasswordAuthenticationToken authentication) throws AuthenticationException {
         UserDetails userDetails = null;
-        BadCredentialsException e = null;
+        List<BadCredentialsException> causes = new ArrayList<BadCredentialsException>();
         for (String domainName : domainNames) {
             try {
                 userDetails = retrieveUser(username, authentication, domainName);
             } catch (BadCredentialsException bce) {
                 LOGGER.log(Level.WARNING, "Credential exception tying to authenticate against "+domainName+" domain", bce);
-                e = bce;
+                causes.add(bce);
             }
             if (userDetails!=null) {
                 break;
             }
         }
         if (userDetails==null) {
             LOGGER.log(Level.WARNING, "Exhausted all configured domains and could not authenticate against any.");
-            if (e!=null)    throw e;
-            throw new BadCredentialsException("Either no such user '"+username+"' or incorrect password");
+            if (causes.isEmpty())
+                throw new BadCredentialsException("Either no such user '"+username+"' or incorrect password");
+            else
+                throw new MultiCauseBadCredentialsException("Either no such user '"+username+"' or incorrect password",causes);
         }
         return userDetails;
     }

src/main/java/hudson/plugins/active_directory/ActiveDirectoryUserDetail.java

@@ -63,8 +63,10 @@ public hudson.model.User getJenkinsUser() {
      * @return this
      */
     public UserDetails updateUserInfo() {
+        // the challenge here is to set the name if it's not set, but if the user overrides that
+        //
         hudson.model.User u = getJenkinsUser();
-        if (getDisplayName()!=null)
+        if (getDisplayName()!=null && u.getId().equals(u.getFullName()))
             u.setFullName(getDisplayName());
 
         if (getMail()!=null)

src/main/java/hudson/plugins/active_directory/MultiCauseBadCredentialsException.java

@@ -0,0 +1,44 @@
+package hudson.plugins.active_directory;
+
+import com.google.common.collect.ImmutableList;
+import hudson.util.FlushProofOutputStream;
+import org.acegisecurity.AuthenticationException;
+
+import java.io.PrintStream;
+import java.io.PrintWriter;
+import java.util.Collection;
+import java.util.List;
+
+/**
+ * {@link AuthenticationException} that supports multiple nested causes.
+ *
+ * @author Kohsuke Kawaguchi
+ */
+public class MultiCauseBadCredentialsException extends AuthenticationException {
+    private final List<Throwable> causes;
+
+    public MultiCauseBadCredentialsException(String msg, Collection<? extends Throwable> causes) {
+        super(msg);
+        this.causes = ImmutableList.copyOf(causes);
+    }
+
+    @Override
+    public void printStackTrace(PrintStream s) {
+        PrintWriter w = new PrintWriter(new FlushProofOutputStream(s));
+        printStackTrace(w);
+        w.flush();
+    }
+
+    @Override
+    public void printStackTrace(PrintWriter s) {
+        synchronized (s) {
+            super.printStackTrace(s);
+
+            for (int i = 0; i < causes.size(); i++) {
+                Throwable cause = causes.get(i);
+                s.format("Cause #%s: ", i + 1);
+                cause.printStackTrace(s);
+            }
+        }
+    }
+}