Fixing issue in Cache where duration = 0 would not read/write from ca…

…che. This prevented the creation of non expiring cache entries in APC and memcache.

Adding a return false to FileEngine as it was omitted in the past.
Fixes #1120

cake/libs/cache.php

@@ -296,7 +296,7 @@ function write($key, $value, $config = null) {
 		}
 		$key = $self->_engines[$config]->key($key);
 
-		if (!$key || is_resource($value) || $settings['duration'] < 1) {
+		if (!$key || is_resource($value)) {
 			return false;
 		}
 

cake/libs/cache/file.php

@@ -265,6 +265,7 @@ function __active() {
 		if ($this->_init && !is_writable($this->settings['path'])) {
 			$this->_init = false;
 			trigger_error(sprintf(__('%s is not writable', true), $this->settings['path']), E_USER_WARNING);
+			return false;
 		}
 		return true;
 	}

cake/tests/cases/libs/cache.test.php

@@ -120,14 +120,15 @@ function testConfigWithLibAndPluginEngines() {
  */
 	function testInvaidConfig() {
 		$this->expectError();
-		Cache::config('Invalid', array(
+		Cache::config('invalid', array(
 			'engine' => 'File',
 			'duration' => '+1 year',
 			'prefix' => 'testing_invalid_',
 			'path' => 'data/',
-			'serialize' => true
+			'serialize' => true,
+			'random' => 'wii'
 		));
-		$read = Cache::read('Test', 'Invalid');
+		$read = Cache::read('Test', 'invalid');
 		$this->assertEqual($read, null);
 	}
 

cake/tests/cases/libs/cache/memcache.test.php

@@ -303,4 +303,19 @@ function testConfigurationConflict() {
 		Cache::delete('short_duration_test', 'short_memcache');
 	}
 
+/**
+ * test that a 0 duration can succesfully write.
+ *
+ * @return void
+ */
+	function testZeroDuration() {
+		Cache::config('memcache', array('duration' => 0));
+		$result = Cache::write('test_key', 'written!', 'memcache');
+
+		$this->assertTrue($result, 'Could not write with duration 0');
+		$result = Cache::read('test_key', 'memcache');
+		$this->assertEqual($result, 'written!');
+
+	}
+
 }