Simplify VCS-based theme checker.

Puc/v4/UpdateChecker.php

@@ -722,10 +722,12 @@ if ( !class_exists('Puc_v4_UpdateChecker', false) ):
 		 * This is basically a simplified version of the get_file_data() function from /wp-includes/functions.php.
 		 * It's intended as a utility for subclasses that detect updates by parsing files in a VCS.
 		 *
-		 * @param string $content File contents.
+		 * @param string|null $content File contents.
 		 * @return string[]
 		 */
 		public function getFileHeader($content) {
+			$content = (string) $content;
+
 			//WordPress only looks at the first 8 KiB of the file, so we do the same.
 			$content = substr($content, 0, 8192);
 			//Normalize line endings.

Puc/v4/Utils.php

@@ -0,0 +1,65 @@
+<?php
+
+if ( !class_exists('Puc_v4_Utils', false) ):
+
+	class Puc_v4_Utils {
+		/**
+		 * Get a value from a nested array or object based on a path.
+		 *
+		 * @param array|object $array Get an entry from this array.
+		 * @param array|string $path A list of array keys in hierarchy order, or a string path like "foo.bar.baz".
+		 * @param mixed $default The value to return if the specified path is not found.
+		 * @param string $separator Path element separator. Only applies to string paths.
+		 * @return mixed
+		 */
+		public static function get($array, $path, $default = null, $separator = '.') {
+			if ( is_string($path) ) {
+				$path = explode($separator, $path);
+			}
+			if ( empty($path) ) {
+				return $default;
+			}
+
+			//Follow the $path into $input as far as possible.
+			$currentValue = $array;
+			$pathExists = true;
+			foreach ($path as $node) {
+				if ( is_array($currentValue) && array_key_exists($node, $currentValue) ) {
+					$currentValue = $currentValue[$node];
+				} else if ( is_object($currentValue) && property_exists($currentValue, $node) ) {
+					$currentValue = $currentValue->$node;
+				} else {
+					$pathExists = false;
+					break;
+				}
+			}
+
+			if ( $pathExists ) {
+				return $currentValue;
+			}
+			return $default;
+		}
+
+		/**
+		 * Get the first array element that is not empty.
+		 *
+		 * @param array $values
+		 * @param mixed|null $default Returns this value if there are no non-empty elements.
+		 * @return mixed|null
+		 */
+		public static function findNotEmpty($values, $default = null) {
+			if ( empty($values) ) {
+				return $default;
+			}
+
+			foreach ($values as $value) {
+				if ( !empty($value) ) {
+					return $value;
+				}
+			}
+
+			return $default;
+		}
+	}
+
+endif;

Puc/v4/Vcs/ThemeUpdateChecker.php

@@ -39,7 +39,6 @@ if ( !class_exists('Puc_v4_Vcs_ThemeUpdateChecker', false) ):
 			$updateSource = $api->chooseReference($this->branch);
 			if ( $updateSource ) {
 				$ref = $updateSource->name;
-				$update->version = $updateSource->version;
 				$update->download_url = $updateSource->downloadUrl;
 			} else {
 				$ref = $this->branch;
@@ -47,24 +46,18 @@ if ( !class_exists('Puc_v4_Vcs_ThemeUpdateChecker', false) ):
 
 			//Get headers from the main stylesheet in this branch/tag. Its "Version" header and other metadata
 			//are what the WordPress install will actually see after upgrading, so they take precedence over releases/tags.
-			$remoteStylesheet = $api->getRemoteFile('style.css', $ref);
-			if ( !empty($remoteStylesheet) ) {
-				$remoteHeader = $this->getFileHeader($remoteStylesheet);
-				if ( !empty($remoteHeader['Version']) ) {
-					$update->version = $remoteHeader['Version'];
-				}
-				if ( !empty($remoteHeader['ThemeURI']) ) {
-					$update->details_url = $remoteHeader['ThemeURI'];
-				}
-			}
+			$remoteHeader = $this->getFileHeader($api->getRemoteFile('style.css', $ref));
+			$update->version = Puc_v4_Utils::findNotEmpty(array(
+				$remoteHeader['Version'],
+				Puc_v4_Utils::get($updateSource, 'version'),
+			));
 
 			//The details URL defaults to the Theme URI header or the repository URL.
-			if ( empty($update->details_url) ) {
-				$update->details_url = $this->theme->get('ThemeURI');
-			}
-			if ( empty($update->details_url) ) {
-				$update->details_url = $this->metadataUrl;
-			}
+			$update->details_url = Puc_v4_Utils::findNotEmpty(array(
+				$remoteHeader['ThemeURI'],
+				$this->theme->get('ThemeURI'),
+				$this->metadataUrl,
+			));
 
 			if ( empty($update->version) ) {
 				//It looks like we didn't find a valid update after all.