Index: test/unit/RegisterTests.pm
===================================================================
--- test/unit/RegisterTests.pm	(Revision 12441)
+++ test/unit/RegisterTests.pm	(Arbeitskopie)
@@ -644,6 +644,99 @@
     };
 }
 
+
+# Purpose:  Test behaviour of duplicate activation (Item3105)
+# Verifies: Most of the things which are verified during normal
+#           registration with Verification, plus Oops for
+#           duplicate verification
+sub test_duplicateActivation {
+    my $this = shift;
+
+    # Start similar to registration with verification
+    $TWiki::cfg{Register}{NeedVerification}  =  1;
+    my $query = CGI->new({'TopicName'     => ['TWikiRegistration'],
+                          'Twk1Email'     => [$testUserEmail],
+                          'Twk1WikiName'  => [$testUserWikiName],
+                          'Twk1Name'      => ['Test User'],
+                          'Twk1LoginName' => [$testUserLoginName],
+                          'Twk1FirstName' => ['Test'],
+                          'Twk1LastName'  => ['User'],
+                          'action'        => ['register'],
+                      });
+    $query->path_info( "/$peopleWeb/TWikiRegistration" );
+    my $twiki = TWiki->new($TWiki::cfg{DefaultUserName}, $query);
+    $twiki->{net}->setMailHandler(\&sentMail);
+    try {
+        TWiki::UI::Register::register_cgi($twiki);
+    } catch TWiki::OopsException with {
+        my $e = shift;
+        $this->assert_str_equals("attention", $e->{template},$e->stringify());
+        $this->assert_str_equals("confirm", $e->{def}, $e->stringify());
+        $this->assert_matches(qr/$testUserEmail/, $e->stringify());
+    } catch TWiki::AccessControlException with {
+        my $e = shift;
+        $this->assert(0, $e->stringify);
+    } catch Error::Simple with {
+        $this->assert(0, shift->stringify());
+    } otherwise {
+        $this->assert(0, "expected an oops redirect");
+    };
+    @mails = ();
+    $twiki->finish();
+
+    # For verification process everything including finish(), so don't just
+    # call verifyEmails
+    my $code = shift || $testUserWikiName.".foo";
+    $query = CGI->new ({'code'   => [$code],
+                        'action' => ['verify'],
+                    });
+    $query->path_info( "/$peopleWeb/TWikiRegistration" );
+    $twiki = TWiki->new($TWiki::cfg{DefaultUserName},$query);
+    $twiki->{net}->setMailHandler(\&sentMail);
+    try {
+        TWiki::UI::Register::register_cgi($twiki);
+    } catch TWiki::OopsException with {
+        my $e = shift;
+        $this->assert_str_equals("attention", $e->{template}, $e->stringify());
+        $this->assert_str_equals("thanks", $e->{def}, $e->stringify());
+    } catch TWiki::AccessControlException with {
+        my $e = shift;
+        $this->assert(0, $e->stringify);
+    } catch Error::Simple with {
+        $this->assert(0, shift->stringify());
+    } otherwise {
+        $this->assert(0, "expected an oops redirect");
+    };
+    @mails = ();
+    $twiki->finish();
+
+    # and now for something completely different: Do it all over again
+    $query = CGI->new ({'code'   => [$code],
+                        'action' => ['verify'],
+                    });
+    $query->path_info( "/$peopleWeb/TWikiRegistration" );
+    $twiki = TWiki->new($TWiki::cfg{DefaultUserName},$query);
+    $twiki->{net}->setMailHandler(\&sentMail);
+    try {
+        TWiki::UI::Register::register_cgi($twiki);
+    } catch TWiki::OopsException with {
+        my $e = shift;
+        $this->assert_str_equals("attention", $e->{template}, $e->stringify());
+        $this->assert_str_equals("duplicate_activation", $e->{def}, $e->stringify());
+        $this->assert_equals(0, scalar(@mails));
+    } catch TWiki::AccessControlException with {
+        my $e = shift;
+        $this->assert(0, $e->stringify);
+    } catch Error::Simple with {
+        $this->assert(0, shift->stringify());
+    } otherwise {
+        $this->assert(0, "expected an oops redirect");
+    };
+    @mails = ();
+    $twiki->finish();
+}
+
+
 ################################################################################
 ################################ RESET PASSWORD TESTS ##########################
 
@@ -843,8 +936,10 @@
 }
 
 =pod
+
 Create an incomplete registration, and try to finish it off.
 Once complete, try again - the second attempt at completion should fail.
+
 =cut
 
 sub test_UnregisteredUser {
@@ -855,7 +950,7 @@
     my $result = TWiki::UI::Register::_getRegDetailsByCode($code, $TWiki::cfg{RegistrationApprovals});
     $this->assert_equals("homer", $result->{doh} );
 
-    my $result2 = TWiki::UI::Register::_reloadUserContext($code, $TWiki::cfg{RegistrationApprovals});
+    my $result2 = TWiki::UI::Register::_reloadUserContext($session, $code, $TWiki::cfg{RegistrationApprovals});
     $this->assert_deep_equals($result2, $regSave);
 
     try {
@@ -1025,8 +1120,11 @@
 
 
 =pod
+
   call this if you want to make spaces and \ns visible
+
 =cut
+
 sub visible {
   return $_[0];
  my ($a) = @_;
Index: templates/messages.tmpl
===================================================================
--- templates/messages.tmpl	(Revision 12441)
+++ templates/messages.tmpl	(Arbeitskopie)
@@ -234,6 +234,12 @@
 
 %MAKETEXT{"Please contact [_1] if you have any questions." args="<a href='mailto:%WIKIWEBMASTER%?subject=%ENCODE{"%WIKITOOLNAME% Registration Question"}%'>%WIKIWEBMASTER%</a>"}%
 %TMPL:END%
+%TMPL:DEF{"duplicate_activation"}%
+---+++ %MAKETEXT{"You are already registered"}%
+%MAKETEXT{"The name [_1] has already been registered successfully." args="'%PARAM1%'"}%
+
+%MAKETEXT{"Please contact [_1] if you have any questions." args="<a href='mailto:%WIKIWEBMASTER%?subject=%ENCODE{"%WIKITOOLNAME% Registration Question"}%'>%WIKIWEBMASTER%</a>"}%
+%TMPL:END%
 %TMPL:DEF{"bad_loginname"}%
 ---+++ %MAKETEXT{"Incorrect [_1]" args="%TWIKIWEB%.LoginName"}%
 %MAKETEXT{"'[_1]' is not a valid [_2] " args="%PARAM1%,%TWIKIWEB%.LoginName"}%
Index: lib/TWiki/UI/Register.pm
===================================================================
--- lib/TWiki/UI/Register.pm	(Revision 12441)
+++ lib/TWiki/UI/Register.pm	(Arbeitskopie)
@@ -729,7 +729,7 @@
     unless( $code ) {
         throw Error::Simple( 'verifyEmailAddress: no verification code!');
     }
-    my $data = _reloadUserContext( $code, $tempUserDir );
+    my $data = _reloadUserContext( $session, $code, $tempUserDir );
 
     if (! exists $data->{Email}) {
         throw Error::Simple( 'verifyEmailAddress: no email address!');
@@ -770,7 +770,7 @@
 
 	my $data;
 	if ($TWiki::cfg{Register}{NeedVerification}) {
-		$data = _reloadUserContext( $code, $tempUserDir );
+		$data = _reloadUserContext( $session, $code, $tempUserDir );
 		_deleteUserContext( $code, $tempUserDir );
 	} else {
 	    $data = _getDataFromQuery( $query, $query->param() );
@@ -1217,16 +1217,29 @@
 # Dies if loads and does not match.
 # Returns the users data hash if succeeded.
 # Returns () if not found.
+# Assumptions: In error handling we assume that the verification code
+#              starts with the wikiname under consideration, and that the
+#              random code does not contain a '.'.
 sub _reloadUserContext {
-    my( $code, $tmpDir ) = @_;
+    my( $session, $code, $tmpDir ) = @_;
 
     ASSERT($code) if DEBUG;
 
     my $verificationFilename = _verificationCodeFilename( $code, $tmpDir );
     unless (-f $verificationFilename){
-        throw TWiki::OopsException( 'attention',
-                                    def => 'bad_ver_code',
-                                    params => [ $code, '.' ] );
+        my ($wikiName)  =  $code =~ /(.*)\./;
+        if ($session->{users}->lookupWikiName($wikiName)) {
+            throw TWiki::OopsException('attention',
+                                       def => 'duplicate_activation',
+                                       params => [$wikiName],
+                                      );
+        }
+        else {
+            throw TWiki::OopsException('attention',
+                                       def => 'bad_ver_code',
+                                       params => [ $code, '.' ],
+                                      );
+        }
     }
 
     my $data = _getRegDetailsByCode($code, $tmpDir);