diff --git a/src/applications/config/check/PhabricatorWebServerSetupCheck.php b/src/applications/config/check/PhabricatorWebServerSetupCheck.php
--- a/src/applications/config/check/PhabricatorWebServerSetupCheck.php
+++ b/src/applications/config/check/PhabricatorWebServerSetupCheck.php
@@ -23,7 +23,7 @@
     }
 
     $base_uri = PhabricatorEnv::getEnvConfig('phabricator.base-uri');
-    if (!strlen($base_uri)) {
+    if (!phutil_nonempty_string($base_uri)) {
       // If `phabricator.base-uri` is not set then we can't really do
       // anything.
       return;
diff --git a/src/applications/config/controller/services/PhabricatorConfigDatabaseStatusController.php b/src/applications/config/controller/services/PhabricatorConfigDatabaseStatusController.php
--- a/src/applications/config/controller/services/PhabricatorConfigDatabaseStatusController.php
+++ b/src/applications/config/controller/services/PhabricatorConfigDatabaseStatusController.php
@@ -837,7 +837,7 @@
 
     $parts = array();
     foreach ($properties as $key => $property) {
-      if (!strlen($property)) {
+      if (!phutil_nonempty_string($property)) {
         continue;
       }
 
diff --git a/src/applications/diffusion/request/DiffusionGitRequest.php b/src/applications/diffusion/request/DiffusionGitRequest.php
--- a/src/applications/diffusion/request/DiffusionGitRequest.php
+++ b/src/applications/diffusion/request/DiffusionGitRequest.php
@@ -3,7 +3,7 @@
 final class DiffusionGitRequest extends DiffusionRequest {
 
   protected function isStableCommit($symbol) {
-    return preg_match('/^[a-f0-9]{40}\z/', $symbol);
+    return $symbol && preg_match('/^[a-f0-9]{40}\z/', $symbol);
   }
 
   public function getBranch() {
diff --git a/src/applications/files/controller/PhabricatorFileLightboxController.php b/src/applications/files/controller/PhabricatorFileLightboxController.php
--- a/src/applications/files/controller/PhabricatorFileLightboxController.php
+++ b/src/applications/files/controller/PhabricatorFileLightboxController.php
@@ -20,7 +20,7 @@
       return new Aphront404Response();
     }
 
-    if (strlen($comment)) {
+    if (phutil_nonempty_string($comment)) {
       $xactions = array();
       $xactions[] = id(new PhabricatorFileTransaction())
         ->setTransactionType(PhabricatorTransactions::TYPE_COMMENT)
diff --git a/src/applications/files/document/render/PhabricatorDocumentRenderingEngine.php b/src/applications/files/document/render/PhabricatorDocumentRenderingEngine.php
--- a/src/applications/files/document/render/PhabricatorDocumentRenderingEngine.php
+++ b/src/applications/files/document/render/PhabricatorDocumentRenderingEngine.php
@@ -208,12 +208,12 @@
     $this->activeEngine = $engine;
 
     $encode_setting = $request->getStr('encode');
-    if (strlen($encode_setting)) {
+    if (phutil_nonempty_string($encode_setting)) {
       $engine->setEncodingConfiguration($encode_setting);
     }
 
     $highlight_setting = $request->getStr('highlight');
-    if (strlen($highlight_setting)) {
+    if (phutil_nonempty_string($highlight_setting)) {
       $engine->setHighlightingConfiguration($highlight_setting);
     }
 
diff --git a/src/applications/metamta/management/PhabricatorMailManagementSendTestWorkflow.php b/src/applications/metamta/management/PhabricatorMailManagementSendTestWorkflow.php
--- a/src/applications/metamta/management/PhabricatorMailManagementSendTestWorkflow.php
+++ b/src/applications/metamta/management/PhabricatorMailManagementSendTestWorkflow.php
@@ -74,7 +74,7 @@
     $viewer = $this->getViewer();
 
     $type = $args->getArg('type');
-    if (!strlen($type)) {
+    if (!phutil_nonempty_string($type)) {
       $type = PhabricatorMailEmailMessage::MESSAGETYPE;
     }
 
diff --git a/src/applications/people/mail/PhabricatorPeopleEmailLoginMailEngine.php b/src/applications/people/mail/PhabricatorPeopleEmailLoginMailEngine.php
--- a/src/applications/people/mail/PhabricatorPeopleEmailLoginMailEngine.php
+++ b/src/applications/people/mail/PhabricatorPeopleEmailLoginMailEngine.php
@@ -64,7 +64,7 @@
     $message_body = PhabricatorAuthMessage::loadMessageText(
       $recipient,
       $message_key);
-    if (strlen($message_body)) {
+    if (phutil_nonempty_string($message_body)) {
       $body[] = $this->newRemarkupText($message_body);
     }
 
diff --git a/src/applications/repository/storage/PhabricatorRepository.php b/src/applications/repository/storage/PhabricatorRepository.php
--- a/src/applications/repository/storage/PhabricatorRepository.php
+++ b/src/applications/repository/storage/PhabricatorRepository.php
@@ -1160,7 +1160,7 @@
    */
   public function getRemoteURIObject() {
     $raw_uri = $this->getDetail('remote-uri');
-    if (!strlen($raw_uri)) {
+    if (!phutil_nonempty_string($raw_uri)) {
       return new PhutilURI('');
     }
 
diff --git a/src/applications/repository/storage/PhabricatorRepositoryURI.php b/src/applications/repository/storage/PhabricatorRepositoryURI.php
--- a/src/applications/repository/storage/PhabricatorRepositoryURI.php
+++ b/src/applications/repository/storage/PhabricatorRepositoryURI.php
@@ -752,7 +752,7 @@
     // without requiring an index rebuild.
 
     $ssh_host = PhabricatorEnv::getEnvConfig('diffusion.ssh-host');
-    if (strlen($ssh_host)) {
+    if (phutil_nonempty_string($ssh_host)) {
       $domain_map['<ssh-host>'] = $ssh_host;
     }
 
diff --git a/src/applications/search/controller/PhabricatorSearchController.php b/src/applications/search/controller/PhabricatorSearchController.php
--- a/src/applications/search/controller/PhabricatorSearchController.php
+++ b/src/applications/search/controller/PhabricatorSearchController.php
@@ -13,7 +13,7 @@
     $viewer = $this->getViewer();
     $query = $request->getStr('query');
 
-    if ($request->getStr('jump') != 'no' && strlen($query)) {
+    if ($request->getStr('jump') != 'no' && phutil_nonempty_string($query)) {
       $jump_uri = id(new PhabricatorDatasourceEngine())
         ->setViewer($viewer)
         ->newJumpURI($query);