diff --git a/src/applications/auth/controller/PhabricatorAuthRegisterController.php b/src/applications/auth/controller/PhabricatorAuthRegisterController.php
--- a/src/applications/auth/controller/PhabricatorAuthRegisterController.php
+++ b/src/applications/auth/controller/PhabricatorAuthRegisterController.php
@@ -18,7 +18,7 @@
     $invite = $this->loadInvite();
 
     $is_setup = false;
-    if (strlen($account_key)) {
+    if (phutil_nonempty_string($account_key)) {
       $result = $this->loadAccountForRegistrationOrLinking($account_key);
       list($account, $provider, $response) = $result;
       $is_default = false;
@@ -244,9 +244,9 @@
 
     $require_real_name = PhabricatorEnv::getEnvConfig('user.require-real-name');
 
-    $e_username = strlen($value_username) ? null : true;
+    $e_username = phutil_nonempty_string($value_username) ? null : true;
     $e_realname = $require_real_name ? true : null;
-    $e_email = strlen($value_email) ? null : true;
+    $e_email = phutil_nonempty_string($value_email) ? null : true;
     $e_password = true;
     $e_captcha = true;
 
diff --git a/src/applications/base/controller/PhabricatorController.php b/src/applications/base/controller/PhabricatorController.php
--- a/src/applications/base/controller/PhabricatorController.php
+++ b/src/applications/base/controller/PhabricatorController.php
@@ -74,7 +74,7 @@
       $session_engine = new PhabricatorAuthSessionEngine();
 
       $phsid = $request->getCookie(PhabricatorCookies::COOKIE_SESSION);
-      if (strlen($phsid)) {
+      if (phutil_nonempty_string($phsid)) {
         $session_user = $session_engine->loadUserForSession(
           PhabricatorAuthSession::TYPE_WEB,
           $phsid);
diff --git a/src/view/form/control/AphrontFormControl.php b/src/view/form/control/AphrontFormControl.php
--- a/src/view/form/control/AphrontFormControl.php
+++ b/src/view/form/control/AphrontFormControl.php
@@ -172,7 +172,7 @@
       $this->renderInput());
 
     $error = null;
-    if (strlen($this->getError())) {
+    if ($this->getError()) {
       $error = $this->getError();
       if ($error === true) {
         $error = phutil_tag(
@@ -187,7 +187,7 @@
       }
     }
 
-    if (strlen($this->getLabel())) {
+    if (phutil_nonempty_string($this->getLabel())) {
       $label = phutil_tag(
         'label',
         array(
@@ -203,7 +203,7 @@
       $custom_class .= ' aphront-form-control-nolabel';
     }
 
-    if (strlen($this->getCaption())) {
+    if (phutil_nonempty_string($this->getCaption())) {
       $caption = phutil_tag(
         'div',
         array('class' => 'aphront-form-caption'),