diff --git a/ext/danbooru_api/main.php b/ext/danbooru_api/main.php
index 987ee8c4..2b475a9e 100644
--- a/ext/danbooru_api/main.php
+++ b/ext/danbooru_api/main.php
@@ -208,6 +208,7 @@ class DanbooruApi extends Extension {
 
 				// Fire off an event which should process the new file and add it to the db
 				$fileinfo = pathinfo($filename);
+				$metadata = array();
 				$metadata['filename'] = $fileinfo['basename'];
 				$metadata['extension'] = $fileinfo['extension'];
 				$metadata['tags'] = $posttags;
diff --git a/ext/sitemap/main.php b/ext/sitemap/main.php
index 3044ffe7..056d07fe 100644
--- a/ext/sitemap/main.php
+++ b/ext/sitemap/main.php
@@ -62,7 +62,9 @@ class XMLSitemap extends Extension {
         private function handle_full_sitemap()
         {
                 global $database, $config;
+
                 // add index
+                $index = array();
                 $index[0] = $config->get_string("front_page");
                 $this->add_sitemap_queue($index, "weekly", "1");
 
diff --git a/ext/statsd/main.php b/ext/statsd/main.php
index 4a9e4b81..a365183a 100644
--- a/ext/statsd/main.php
+++ b/ext/statsd/main.php
@@ -99,7 +99,7 @@ class StatsDInterface extends Extension {
 
         // Wrap this in a try/catch - failures in any of this should be silently ignored
         try {
-			$parts = explode(":", STATSD_HOST);
+            $parts = explode(":", STATSD_HOST);
             $host = $parts[0];
             $port = $parts[1];
             $fp = fsockopen("udp://$host", $port, $errno, $errstr);
@@ -109,6 +109,7 @@ class StatsDInterface extends Extension {
             }
             fclose($fp);
         } catch (Exception $e) {
+            // ignore any failures.
         }
     }
 }
diff --git a/ext/tag_editcloud/script.js b/ext/tag_editcloud/script.js
index ae4d8eb1..b71818c4 100644
--- a/ext/tag_editcloud/script.js
+++ b/ext/tag_editcloud/script.js
@@ -20,7 +20,7 @@ Array.prototype.editcloud_remove = function (ele) {
 
 var hide_text = null;
 function tageditcloud_toggle_extra(hide) {
-	if (hide_text == null) {
+	if (hide_text === null) {
 		hide_text = hide.innerHTML;
 	}
 
diff --git a/ext/tag_history/main.php b/ext/tag_history/main.php
index 9550215f..b6e6605c 100644
--- a/ext/tag_history/main.php
+++ b/ext/tag_history/main.php
@@ -135,13 +135,13 @@ class Tag_History extends Extension {
 			// there is no history entry with that id so either the image was deleted
 			// while the user was viewing the history, someone is playing with form
 			// variables or we have messed up in code somewhere.
-			/* calling die() is probably not a good idea, we should throw an Exception */
+			/* FIXME: calling die() is probably not a good idea, we should throw an Exception */
 			die("Error: No tag history with specified id was found.");
 		}
 		
 		// lets get the values out of the result
 		$stored_result_id = $result['id'];
-		$stored_image_id = $result['image_id'];
+		$stored_image_id = int_escape($result['image_id']);
 		$stored_tags = $result['tags'];
 		
 		log_debug("tag_history", 'Reverting tags of Image #'.$stored_image_id.' to ['.$stored_tags.']');
@@ -267,7 +267,7 @@ class Tag_History extends Extension {
 
 		log_info("tag_history", 'Attempting to revert edits where '.implode(" and ", $select_code)." (".implode(" / ", $select_args).")");
 		
-		// Get all the images that the given IP has changed tags on (within the timeframe) that were last editied by the given IP
+		// Get all the images that the given IP has changed tags on (within the timeframe) that were last edited by the given IP
 		$result = $database->get_col('
 				SELECT t1.image_id
 				FROM tag_histories t1
@@ -304,8 +304,8 @@ class Tag_History extends Extension {
 				}
 				
 				// lets get the values out of the result
-				$stored_result_id = $result['id'];
-				$stored_image_id = $result['image_id'];
+				$stored_result_id = int_escape($result['id']);
+				$stored_image_id = int_escape($result['image_id']);
 				$stored_tags = $result['tags'];
 				
 				log_debug("tag_history", 'Reverting tags of Image #'.$stored_image_id.' to ['.$stored_tags.']');
@@ -350,8 +350,8 @@ class Tag_History extends Extension {
 			$entries++;
 		}
 
-		// add a history entry	
-		$row = $database->execute("
+		// add a history entry
+		$database->execute("
 				INSERT INTO tag_histories(image_id, tags, user_id, user_ip, date_set)
 				VALUES (?, ?, ?, ?, now())",
 				array($image->id, $new_tags, $user->id, $_SERVER['REMOTE_ADDR']));
diff --git a/ext/upload/main.php b/ext/upload/main.php
index 4c3d19b4..e6b8dfaa 100644
--- a/ext/upload/main.php
+++ b/ext/upload/main.php
@@ -277,6 +277,7 @@ class Upload extends Extension {
 				}
 				
 				$pathinfo = pathinfo($file['name']);
+				$metadata = array();
 				$metadata['filename'] = $pathinfo['basename'];
 				$metadata['extension'] = $pathinfo['extension'];
 				$metadata['tags'] = $tags;
@@ -347,6 +348,7 @@ class Upload extends Extension {
 		}else{
 			global $user;
 			$pathinfo = pathinfo($url);
+			$metadata = array();
 			$metadata['filename'] = $filename;
 			$metadata['extension'] = getExtension($headers['Content-Type']) ?: $pathinfo['extension'];
 			$metadata['tags'] = $tags;