v1.29 - Proper fix for Last-modified header to use the date within th…

…e cached podcast

CHANGELOG.txt

@@ -1,6 +1,9 @@
 Changelog
 =========
 
+1.29 2021-03-01 * Proper fix for Last-modified header to use the date within
+                  the cached podcast.
+
 1.28 2021-03-01 * Fixes for caching so it properly ignores files which are still
                   mid-upload
                 * Now sends Content-length header

README.md

@@ -1,6 +1,6 @@
 [![Testing dir2cast](https://github.com/ben-xo/dir2cast/actions/workflows/testing.yml/badge.svg)](https://github.com/ben-xo/dir2cast/actions/workflows/testing.yml)
 
-dir2cast by Ben XO v1.28 (2021-03-01)
+dir2cast by Ben XO v1.29 (2021-03-01)
 ================================================================================
 
 https://github.com/ben-xo/dir2cast/

dir2cast.php

@@ -56,7 +56,7 @@
 /* DEFAULTS *********************************************/
 
 // error handler needs these, so let's set them now.
-define('VERSION', '1.28');
+define('VERSION', '1.29');
 define('DIR2CAST_HOMEPAGE', 'https://github.com/ben-xo/dir2cast/');
 define('GENERATOR', 'dir2cast ' . VERSION . ' by Ben XO (' . DIR2CAST_HOMEPAGE . ')');
 
@@ -1344,6 +1344,17 @@ public function generate()
                 throw new RuntimeException("serve_from_cache set, but cache file not found");
 
             $output = file_get_contents($this->temp_file); // serve cached copy
+
+            // extract lastBuiltDate from the cache file. We can't simply use filemtime() of the cache file as
+            // the mtime is refreshed (to stop us continually rescanning for new content) Also, we don't want to
+            // parse the whole file, so it's okay to carefully extract it with a regex here, even though that's
+            // not usually recommended. The regex is chosen to ensure the captured text can't lead to header injection.
+
+            preg_match('#<lastBuildDate>([0-9a-zA-Z,:+ ]{1,64})</lastBuildDate>#', $output, $matches);
+            if(isset($matches[1]))
+            {
+                $this->setLastBuildDate($matches[1]);
+            }
         }
         else
         {
@@ -1359,14 +1370,6 @@ public function isCached()
     {
         return file_exists($this->temp_file) && filesize($this->temp_file);
     }
-
-    public function getLastBuildDate()
-    {
-       if($this->isCached())
-           return date('r', filemtime($this->temp_file));
-       else
-           return $this->__call('getLastBuildDate', array());
-    }
 }
 
 class Locking_Cached_Dir_Podcast extends Cached_Dir_Podcast

test/Cached_Dir_PodcastTest.php

@@ -132,6 +132,16 @@ public function test_lastBuildDate_is_valid_whether_served_from_cache_or_not()
         $this->assertTrue($mp2->isCached());
 
         $this->assertEquals($lastBuildDate, $mp2->getLastBuildDate());
+        unset($mp2);
+
+        clearstatcache();
+        age_dir_by('.', 3600);
+        sleep(1); // not much choice here!
+        $mp3 = $this->newPodcast();
+        $mp3->generate();
+
+        clearstatcache();
+        $this->assertEquals($lastBuildDate, $mp3->getLastBuildDate());
     }
 
     public function tearDown(): void