diff --git a/includes/GlobalFunctions.php b/includes/GlobalFunctions.php
index 5be05d1022e..4f3e928ced4 100644
--- a/includes/GlobalFunctions.php
+++ b/includes/GlobalFunctions.php
@@ -1432,7 +1432,6 @@ function wfClientAcceptsGzip( $force = false ) {
 				)
 			) {
 				if ( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
-					$result = false;
 					return $result;
 				}
 				wfDebug( "wfClientAcceptsGzip: client accepts gzip." );
diff --git a/includes/Revision/ContributionsLookup.php b/includes/Revision/ContributionsLookup.php
index 83ff0d8d09e..5ed623f0298 100644
--- a/includes/Revision/ContributionsLookup.php
+++ b/includes/Revision/ContributionsLookup.php
@@ -89,7 +89,6 @@ class ContributionsLookup {
 				$dir = 'prev';
 				$segment = $seg[1];
 			} elseif ( $seg[0] == 'before' ) {
-				$dir = 'next';
 				$segment = $seg[1];
 			} else {
 				$dir = null;
diff --git a/includes/actions/RawAction.php b/includes/actions/RawAction.php
index ff3e521b674..a5d66b45fc8 100644
--- a/includes/actions/RawAction.php
+++ b/includes/actions/RawAction.php
@@ -232,7 +232,6 @@ class RawAction extends FormlessAction {
 
 			if ( $content === null ) {
 				// revision not found (or suppressed)
-				$text = false;
 			} elseif ( !$content instanceof TextContent ) {
 				// non-text content
 				wfHttpError( 415, "Unsupported Media Type", "The requested page uses the content model `"
@@ -247,7 +246,6 @@ class RawAction extends FormlessAction {
 
 				if ( $content === null || $content === false ) {
 					// section not found (or section not supported, e.g. for JS, JSON, and CSS)
-					$text = false;
 				} else {
 					$text = $content->getText();
 				}
diff --git a/includes/libs/objectcache/MemcachedPeclBagOStuff.php b/includes/libs/objectcache/MemcachedPeclBagOStuff.php
index e570b8e3593..f9a403c2f86 100644
--- a/includes/libs/objectcache/MemcachedPeclBagOStuff.php
+++ b/includes/libs/objectcache/MemcachedPeclBagOStuff.php
@@ -196,7 +196,6 @@ class MemcachedPeclBagOStuff extends MemcachedBagOStuff {
 				$casToken = $res['cas'];
 			} else {
 				$result = false;
-				$casToken = null;
 			}
 		} else {
 			$result = $client->get( $routeKey );
diff --git a/includes/preferences/DefaultPreferencesFactory.php b/includes/preferences/DefaultPreferencesFactory.php
index 72291911ab3..3bbd782aced 100644
--- a/includes/preferences/DefaultPreferencesFactory.php
+++ b/includes/preferences/DefaultPreferencesFactory.php
@@ -729,7 +729,6 @@ class DefaultPreferencesFactory implements PreferencesFactory {
 						$t = $lang->userTime( $emailTimestamp, $displayUser );
 						$emailauthenticated = $context->msg( 'emailauthenticated',
 							$time, $d, $t )->parse() . '<br />';
-						$disableEmailPrefs = false;
 						$emailauthenticationclass = 'mw-email-authenticated';
 					} else {
 						$disableEmailPrefs = true;
diff --git a/includes/resourceloader/ResourceLoaderClientHtml.php b/includes/resourceloader/ResourceLoaderClientHtml.php
index 4d31015e01a..0c2e69050bf 100644
--- a/includes/resourceloader/ResourceLoaderClientHtml.php
+++ b/includes/resourceloader/ResourceLoaderClientHtml.php
@@ -395,7 +395,6 @@ JAVASCRIPT;
 		sort( $modules );
 
 		if ( $mainContext->getDebug() && count( $modules ) > 1 ) {
-			$chunks = [];
 			// Recursively call us for every item
 			foreach ( $modules as $name ) {
 				$chunks[] = self::makeLoad( $mainContext, [ $name ], $only, $extraQuery, $nonce );
diff --git a/includes/search/SearchEngine.php b/includes/search/SearchEngine.php
index 268d9ace65e..334f91396c3 100644
--- a/includes/search/SearchEngine.php
+++ b/includes/search/SearchEngine.php
@@ -419,7 +419,6 @@ abstract class SearchEngine {
 
 			foreach ( $allkeywords as $kw ) {
 				if ( strncmp( $query, $kw, strlen( $kw ) ) == 0 ) {
-					$extractedNamespace = null;
 					$parsed = substr( $query, strlen( $kw ) );
 					$allQuery = true;
 					break;
diff --git a/includes/specials/SpecialBlock.php b/includes/specials/SpecialBlock.php
index ab60600faec..cfae60d2c84 100644
--- a/includes/specials/SpecialBlock.php
+++ b/includes/specials/SpecialBlock.php
@@ -857,7 +857,6 @@ class SpecialBlock extends FormSpecialPage {
 		if ( $isPartialBlock ) {
 			if ( isset( $data['PageRestrictions'] ) && $data['PageRestrictions'] !== '' ) {
 				$titles = explode( "\n", $data['PageRestrictions'] );
-				$pageRestrictions = [];
 				foreach ( $titles as $title ) {
 					$pageRestrictions[] = PageRestriction::newFromTitle( $title );
 				}
diff --git a/maintenance/fixMergeHistoryCorruption.php b/maintenance/fixMergeHistoryCorruption.php
index 896830c51c7..ef2d7bb259f 100644
--- a/maintenance/fixMergeHistoryCorruption.php
+++ b/maintenance/fixMergeHistoryCorruption.php
@@ -53,11 +53,9 @@ class FixMergeHistoryCorruption extends Maintenance {
 		$dryRun = true;
 		if ( $this->hasOption( 'dry-run' ) && $this->hasOption( 'delete' ) ) {
 			$this->fatalError( 'Cannot do both --dry-run and --delete.' );
-		} elseif ( $this->hasOption( 'dry-run' ) ) {
-			$dryRun = true;
 		} elseif ( $this->hasOption( 'delete' ) ) {
 			$dryRun = false;
-		} else {
+		} elseif ( !$this->hasOption( 'dry-run' ) ) {
 			$this->fatalError( 'Either --dry-run or --delete must be specified.' );
 		}
 
diff --git a/maintenance/getConfiguration.php b/maintenance/getConfiguration.php
index b2e1c57bdd1..972167a4fde 100644
--- a/maintenance/getConfiguration.php
+++ b/maintenance/getConfiguration.php
@@ -122,7 +122,6 @@ class GetConfiguration extends Maintenance {
 
 		# Filter out globals based on the regex
 		if ( $this->regex ) {
-			$res = [];
 			foreach ( $GLOBALS as $name => $value ) {
 				if ( preg_match( $this->regex, $name ) ) {
 					$res[$name] = $value;