Make relative path work

Path in the phpbu configuration file should always be absolute or
relative to the position of the config file.

To make this work for teh tar source the path option is now converted
to an absolute path during setup.

Author: sebastianfeldmann

src/Backup/Source/Tar.php

@@ -3,9 +3,11 @@
 
 use phpbu\App\Backup\Target;
 use phpbu\App\Cli\Executable;
+use phpbu\App\Configuration;
 use phpbu\App\Exception;
 use phpbu\App\Result;
 use phpbu\App\Util;
+use Symfony\Component\Finder\Tests\Iterator\FilecontentFilterIteratorTest;
 
 /**
  * Tar source class.
@@ -111,18 +113,32 @@ class Tar extends SimulatorExecutable implements Simulator
      */
     public function setup(array $conf = [])
     {
+        $this->setupPath($conf);
         $this->pathToTar        = Util\Arr::getValue($conf, 'pathToTar', '');
-        $this->path             = Util\Arr::getValue($conf, 'path', '');
         $this->excludes         = Util\Str::toList(Util\Arr::getValue($conf, 'exclude', ''));
         $this->compressProgram  = Util\Arr::getValue($conf, 'compressProgram', '');
         $this->throttle         = Util\Arr::getValue($conf, 'throttle', '');
         $this->forceLocal       = Util\Str::toBoolean(Util\Arr::getValue($conf, 'forceLocal', ''), false);
         $this->ignoreFailedRead = Util\Str::toBoolean(Util\Arr::getValue($conf, 'ignoreFailedRead', ''), false);
         $this->removeSourceDir  = Util\Str::toBoolean(Util\Arr::getValue($conf, 'removeSourceDir', ''), false);
+    }
 
-        if (empty($this->path)) {
+    /**
+     * Setup the path to the directory that should be compressed.
+     *
+     * @param  array $conf
+     * @throws \phpbu\App\Exception
+     */
+    protected function setupPath(array $conf)
+    {
+        $path = Util\Arr::getValue($conf, 'path', '');
+        if (empty($path)) {
             throw new Exception('path option is mandatory');
         }
+        $this->path = Util\Path::toAbsolutePath($path, Configuration::getWorkingDirectory());
+        if (!file_exists($this->path)) {
+            throw new Exception('could not find directory to compress');
+        }
     }
 
     /**