On APT home page (instantiate.php) if there is an emulab user cookie,

we know (suspect) the user has an account, so redirect to the login
page. There is a new Continue as Guest button on the login page in
case that is what the user really wants to do.

www/aptui/instantiate.php

@@ -37,7 +37,7 @@ $dblink = GetDBLink("sa");
 #
 RedirectSecure();
 $this_user = CheckLogin($check_status);
-if (!$ISAPT) {
+if ($ISCLOUD) {
     if (! ($CHECKLOGIN_STATUS & CHECKLOGIN_LOGGEDIN)) {
 	header("Location: login.php");
     }
@@ -52,7 +52,28 @@ $optargs = OptionalPageArguments("create",        PAGEARG_STRING,
 				 "stuffing",      PAGEARG_STRING,
 				 "verify",        PAGEARG_STRING,
 				 "project",       PAGEARG_PROJECT,
+				 "asguest",       PAGEARG_BOOLEAN,
 				 "formfields",    PAGEARG_ARRAY);
+
+if ($ISAPT) {
+    #
+    # If user appears to have an account, go to login page.
+    # Continue as guest on that page.
+    #
+    if (REMEMBERED_ID()) {
+	if (isset($asguest) && $asguest) {
+	    # User clicked on continue as guest. If we do not delete the
+	    # cookie, then user will go through the same loop next time
+            # they click the Home button, since that points here. So delete
+	    # the UID cookie. Not sure I like this.
+	    ClearRememberedID();
+	}
+	else {
+	    header("Location: login.php");
+	}
+    }
+}
+
 if ($ISCLOUD) {
     $profile_default     = "OpenStack";
     $profile_default_pid = "tbres";

www/aptui/login.php

@@ -158,6 +158,13 @@ function SPITFORM($uid, $referrer, $error)
                     id='quickvm_geni_login_button'>Geni User?</button>
         <?php
     }
+    if ($ISAPT) {
+	?>
+                 <a class='btn btn-info btn-sm pull-left'
+	            href='instantiate.php?asguest=1'
+		    type='button'>Continue as Guest</a>
+        <?php
+    }
 ?>
                  <button class='btn btn-primary btn-sm pull-right'
                          id='quickvm_login_modal_button'

www/tbauth.php3

@@ -111,6 +111,12 @@ function REMEMBERED_ID() {
     }
     return null;
 }
+function ClearRememberedID()
+{
+    global $TBEMAILCOOKIE, $WWWHOST;
+    
+    setcookie($TBEMAILCOOKIE, '', 1, "/", $WWWHOST, 0);
+}
 
 #
 # Return the value of the currently logged in uid, or null if not
@@ -396,8 +402,8 @@ function LoginStatus() {
 	    # No hash of the hash, so assume no real cookie either. 
 	    # 
 	    $CHECKLOGIN_STATUS = CHECKLOGIN_NOTLOGGEDIN;
-	    return $CHECKLOGIN_STATUS;
 	}
+	return $CHECKLOGIN_STATUS;
     }
 
     # Cache this now; someone will eventually want it.