diff --git a/src/applications/config/engine/PhabricatorSetupEngine.php b/src/applications/config/engine/PhabricatorSetupEngine.php
index 3a3e6f0419..a4b5c01171 100644
--- a/src/applications/config/engine/PhabricatorSetupEngine.php
+++ b/src/applications/config/engine/PhabricatorSetupEngine.php
@@ -47,7 +47,7 @@ final class PhabricatorSetupEngine
       // because data may be at risk.
       PhabricatorSetupCheck::resetSetupState();
 
-      return PhabricatorSetupCheck::newIssueResponse($issue);
+      return PhabricatorSetupCheck::newIssueResponse($fatal_issue);
     }
 
     $issue_keys = PhabricatorSetupCheck::getUnignoredIssueKeys($issues);
diff --git a/src/applications/diffusion/DiffusionLintSaveRunner.php b/src/applications/diffusion/DiffusionLintSaveRunner.php
index a1a2fe7d32..8f5e51d3b8 100644
--- a/src/applications/diffusion/DiffusionLintSaveRunner.php
+++ b/src/applications/diffusion/DiffusionLintSaveRunner.php
@@ -91,6 +91,7 @@ final class DiffusionLintSaveRunner extends Phobject {
       $this->lintCommit = $this->branch->getLintCommit();
     }
 
+    $all_files = array();
     if ($this->lintCommit) {
       try {
         $commit = $this->lintCommit;
diff --git a/src/applications/diffusion/management/DiffusionRepositoryStorageManagementPanel.php b/src/applications/diffusion/management/DiffusionRepositoryStorageManagementPanel.php
index 2b92c73c97..7bd536495e 100644
--- a/src/applications/diffusion/management/DiffusionRepositoryStorageManagementPanel.php
+++ b/src/applications/diffusion/management/DiffusionRepositoryStorageManagementPanel.php
@@ -292,6 +292,8 @@ final class DiffusionRepositoryStorageManagementPanel
     $viewer = $this->getViewer();
 
     $caught = null;
+    $refs = array();
+
     try {
       $refs = $repository->getAlmanacServiceRefs($viewer, $options);
     } catch (Exception $ex) {
@@ -302,7 +304,6 @@ final class DiffusionRepositoryStorageManagementPanel
 
     $info_view = null;
     if ($caught) {
-      $refs = array();
       $info_view = id(new PHUIInfoView())
         ->setErrors(
           array(
diff --git a/src/applications/files/engine/PhabricatorFileStorageEngine.php b/src/applications/files/engine/PhabricatorFileStorageEngine.php
index 32c8ed13f8..06f53588f3 100644
--- a/src/applications/files/engine/PhabricatorFileStorageEngine.php
+++ b/src/applications/files/engine/PhabricatorFileStorageEngine.php
@@ -320,7 +320,7 @@ abstract class PhabricatorFileStorageEngine extends Phobject {
       }
     }
 
-    if (!$min) {
+    if (!$min || !isset($engine)) {
       return null;
     }
 
diff --git a/src/applications/maniphest/conduit/ManiphestConduitAPIMethod.php b/src/applications/maniphest/conduit/ManiphestConduitAPIMethod.php
index 640e30fee5..855769472a 100644
--- a/src/applications/maniphest/conduit/ManiphestConduitAPIMethod.php
+++ b/src/applications/maniphest/conduit/ManiphestConduitAPIMethod.php
@@ -157,7 +157,8 @@ abstract class ManiphestConduitAPIMethod extends ConduitAPIMethod {
     foreach ($changes as $type => $value) {
       $transaction = clone $template;
       $transaction->setTransactionType($type);
-      if ($type == PhabricatorTransactions::TYPE_COMMENT) {
+      if ($type == PhabricatorTransactions::TYPE_COMMENT &&
+          isset($comments)) {
         $transaction->attachComment(
           id(new ManiphestTransactionComment())
             ->setContent($comments));
diff --git a/src/applications/people/controller/PhabricatorPeopleInviteSendController.php b/src/applications/people/controller/PhabricatorPeopleInviteSendController.php
index 78ab7573ed..d860eb17b6 100644
--- a/src/applications/people/controller/PhabricatorPeopleInviteSendController.php
+++ b/src/applications/people/controller/PhabricatorPeopleInviteSendController.php
@@ -17,6 +17,11 @@ final class PhabricatorPeopleInviteSendController
     $message = $request->getStr('message');
     $emails = $request->getStr('emails');
     $severity = PHUIInfoView::SEVERITY_ERROR;
+
+    $any_valid = false;
+    $all_valid = true;
+    $actions = null;
+
     if ($request->isFormPost()) {
       // NOTE: We aren't using spaces as a delimiter here because email
       // addresses with names often include spaces.
@@ -42,8 +47,6 @@ final class PhabricatorPeopleInviteSendController
           $viewer,
           $email_list);
 
-        $any_valid = false;
-        $all_valid = true;
         foreach ($actions as $action) {
           if ($action->willSend()) {
             $any_valid = true;
diff --git a/src/applications/people/typeahead/PhabricatorPeopleDatasource.php b/src/applications/people/typeahead/PhabricatorPeopleDatasource.php
index c06ba5b458..4a2533a47c 100644
--- a/src/applications/people/typeahead/PhabricatorPeopleDatasource.php
+++ b/src/applications/people/typeahead/PhabricatorPeopleDatasource.php
@@ -35,6 +35,7 @@ final class PhabricatorPeopleDatasource
     $users = $this->executeQuery($query);
 
     $is_browse = $this->getIsBrowse();
+    $handles = array();
 
     if ($is_browse && $users) {
       $phids = mpull($users, 'getPHID');
diff --git a/src/applications/phid/query/PhabricatorObjectListQuery.php b/src/applications/phid/query/PhabricatorObjectListQuery.php
index 78cdbbb9a4..cb679a6c9e 100644
--- a/src/applications/phid/query/PhabricatorObjectListQuery.php
+++ b/src/applications/phid/query/PhabricatorObjectListQuery.php
@@ -100,9 +100,9 @@ final class PhabricatorObjectListQuery extends Phobject {
     // If we're parsing with suffixes, strip them off any tokens and keep
     // track of them for later.
     $suffixes = $this->getSuffixes();
+    $suffix_map = array();
     if ($suffixes) {
       $suffixes = array_fuse($suffixes);
-      $suffix_map = array();
       $stripped_map = array();
       foreach ($name_map as $key => $name) {
         $found_suffixes = array();
diff --git a/src/applications/search/engine/PhabricatorProfileMenuEngine.php b/src/applications/search/engine/PhabricatorProfileMenuEngine.php
index 7fbfe1c2da..dbd95f2fe8 100644
--- a/src/applications/search/engine/PhabricatorProfileMenuEngine.php
+++ b/src/applications/search/engine/PhabricatorProfileMenuEngine.php
@@ -392,6 +392,7 @@ abstract class PhabricatorProfileMenuEngine extends Phobject {
 
   private function loadBuiltinProfileItems($mode) {
     $object = $this->getProfileObject();
+    $builtins = array();
 
     switch ($mode) {
       case self::MODE_GLOBAL:
@@ -403,7 +404,6 @@ abstract class PhabricatorProfileMenuEngine extends Phobject {
           $this->getCustomPHID());
         break;
       case self::MODE_COMBINED:
-        $builtins = array();
         $builtins[] = $this->getBuiltinCustomProfileItems(
           $object,
           $this->getCustomPHID());
diff --git a/src/applications/settings/controller/PhabricatorSettingsMainController.php b/src/applications/settings/controller/PhabricatorSettingsMainController.php
index ded20a8e96..65fb40942b 100644
--- a/src/applications/settings/controller/PhabricatorSettingsMainController.php
+++ b/src/applications/settings/controller/PhabricatorSettingsMainController.php
@@ -114,7 +114,7 @@ final class PhabricatorSettingsMainController
     $crumbs->addTextCrumb($panel->getPanelName());
     $crumbs->setBorder(true);
 
-    if ($this->user) {
+    if (isset($user)) {
       $header_text = pht('Edit Settings: %s', $user->getUserName());
     } else {
       $header_text = pht('Edit Global Settings');
diff --git a/src/infrastructure/cache/PhutilAPCKeyValueCache.php b/src/infrastructure/cache/PhutilAPCKeyValueCache.php
index 9af92ab914..08894204b4 100644
--- a/src/infrastructure/cache/PhutilAPCKeyValueCache.php
+++ b/src/infrastructure/cache/PhutilAPCKeyValueCache.php
@@ -25,10 +25,10 @@ final class PhutilAPCKeyValueCache extends PhutilKeyValueCache {
     $results = array();
     $fetched = false;
     foreach ($keys as $key) {
-      if ($is_apcu) {
-        $result = apcu_fetch($key, $fetched);
+      if (!$is_apcu) {
+        continue;
       }
-
+      $result = apcu_fetch($key, $fetched);
       if ($fetched) {
         $results[$key] = $result;
       }
diff --git a/src/view/phui/PHUICurtainObjectRefView.php b/src/view/phui/PHUICurtainObjectRefView.php
index 855aa855c6..6100f46e04 100644
--- a/src/view/phui/PHUICurtainObjectRefView.php
+++ b/src/view/phui/PHUICurtainObjectRefView.php
@@ -227,6 +227,7 @@ final class PHUICurtainObjectRefView
   }
 
   private function newIconView() {
+    $icon_view = null;
     $handle = $this->handle;
 
     if ($handle) {
diff --git a/src/view/phui/PHUIInfoView.php b/src/view/phui/PHUIInfoView.php
index fa08f0e9dd..2ab16ce105 100644
--- a/src/view/phui/PHUIInfoView.php
+++ b/src/view/phui/PHUIInfoView.php
@@ -84,6 +84,7 @@ final class PHUIInfoView extends AphrontTagView {
       return $this->icon;
     }
 
+    $icon = null;
     switch ($this->getSeverity()) {
       case self::SEVERITY_ERROR:
         $icon = 'fa-exclamation-circle';
diff --git a/src/view/phui/PHUIRemarkupPreviewPanel.php b/src/view/phui/PHUIRemarkupPreviewPanel.php
index 46c0f5cd53..7429b8af8f 100644
--- a/src/view/phui/PHUIRemarkupPreviewPanel.php
+++ b/src/view/phui/PHUIRemarkupPreviewPanel.php
@@ -89,6 +89,7 @@ final class PHUIRemarkupPreviewPanel extends AphrontTagView {
       ),
       $loading);
 
+    $content = null;
     if (!$this->previewType) {
       $header = null;
       if ($this->header) {
diff --git a/support/startup/PhabricatorClientLimit.php b/support/startup/PhabricatorClientLimit.php
index 63a50a3c91..ef528083f0 100644
--- a/support/startup/PhabricatorClientLimit.php
+++ b/support/startup/PhabricatorClientLimit.php
@@ -201,7 +201,7 @@ abstract class PhabricatorClientLimit {
       $bucket = apcu_fetch($bucket_key);
     }
 
-    if (!is_array($bucket)) {
+    if (!isset($bucket) || !is_array($bucket)) {
       $bucket = array();
     }
 
@@ -238,7 +238,7 @@ abstract class PhabricatorClientLimit {
     // If we don't have any buckets stored yet, store the current bucket as
     // the oldest bucket.
     $cur = $this->getCurrentBucketID();
-    if (!$min) {
+    if (!isset($min) || !$min) {
       if ($is_apcu) {
         @apcu_store($min_key, $cur);
       }