Let 'RSSUtils::check_feed_favicon' update existing favicons.

classes/rssutils.php

@@ -594,7 +594,7 @@ class RSSUtils {
 				$favicon_file = ICONS_DIR . "/$feed.ico";
 				$favicon_modified = file_exists($favicon_file) ? filemtime($favicon_file) : -1;
 
-				Debug::log("checking favicon...", Debug::$LOG_VERBOSE);
+				Debug::log("checking favicon for feed $feed...", Debug::$LOG_VERBOSE);
 
 				self::check_feed_favicon($site_url, $feed);
 				$favicon_modified_new = file_exists($favicon_file) ? filemtime($favicon_file) : -1;
@@ -1643,18 +1643,30 @@ class RSSUtils {
 	}
 
 	static function check_feed_favicon($site_url, $feed) {
-		#		print "FAVICON [$site_url]: $favicon_url\n";
-
 		$icon_file = ICONS_DIR . "/$feed.ico";
 
-		if (!file_exists($icon_file)) {
 		$favicon_url = self::get_favicon_url($site_url);
+		if (!$favicon_url) {
+			Debug::log("couldn't find favicon URL in $site_url", Debug::$LOG_VERBOSE);
+			return false;
+		}
 
-			if ($favicon_url) {
 		// Limiting to "image" type misses those served with text/plain
-				$contents = UrlHelper::fetch($favicon_url); // , "image");
+		$contents = UrlHelper::fetch(['url' => $favicon_url]); // , "image");
+		if (!$contents) {
+			Debug::log("fetching favicon $favicon_url failed", Debug::$LOG_VERBOSE);
+			return false;
+		}
+
+		$original_contents = file_exists($icon_file) ? file_get_contents($icon_file) : null;
+		if ($original_contents) {
+			if (strcmp($contents, $original_contents) === 0) {
+				Debug::log("favicon content has not changed", Debug::$LOG_VERBOSE);
+				return $icon_file;
+			}
+			Debug::log("favicon content has changed", Debug::$LOG_VERBOSE);
+		}
 
-				if ($contents) {
 		// Crude image type matching.
 		// Patterns gleaned from the file(1) source code.
 		if (preg_match('/^\x00\x00\x01\x00/', $contents)) {
@@ -1679,23 +1691,25 @@ class RSSUtils {
 		}
 		else {
 			//error_log("check_feed_favicon: favicon_url=$favicon_url isa UNKNOWN type");
-						$contents = "";
+			Debug::log("favicon $favicon_url type is unknown (not updating)", Debug::$LOG_VERBOSE);
-					}
+			return false;
 		}
 
-				if ($contents) {
+		Debug::log("setting contents of $icon_file", Debug::$LOG_VERBOSE);
+
 		$fp = @fopen($icon_file, "w");
+		if (!$fp) {
+			Debug::log("failed to open $icon_file for writing", Debug::$LOG_VERBOSE);
+			return false;
+		}
 
-					if ($fp) {
 		fwrite($fp, $contents);
 		fclose($fp);
 		chmod($icon_file, 0644);
-					}
+		clearstatcache();
-				}
+
-			}
 		return $icon_file;
 	}
-	}
 
 	static function is_gzipped($feed_data) {
 		return strpos(substr($feed_data, 0, 3),