Get real commit for annotated tag

src/Gitonomy/Git/Reference/Tag.php

@@ -14,13 +14,15 @@
 
 use Gitonomy\Git\Exception\ProcessException;
 use Gitonomy\Git\Exception\RuntimeException;
+use Gitonomy\Git\Parser\ReferenceParser;
 use Gitonomy\Git\Parser\TagParser;
 use Gitonomy\Git\Reference;
 
 /**
  * Representation of a tag reference.
  *
  * @author Alexandre Salomé <[email protected]>
+ * @author Bruce Wells <[email protected]>
  */
 class Tag extends Reference
 {
@@ -49,6 +51,32 @@ public function isAnnotated()
         return true;
     }
 
+    /**
+     * Returns the actual commit associated with the tag, and not the hash of the tag if annotated.
+     *
+     * @return Commit
+     */
+    public function getCommit()
+    {
+        if ($this->isAnnotated()) {
+            try {
+                $output = $this->repository->run('show-ref', ['-d', '--tag', $this->revision]);
+                $parser = new ReferenceParser();
+                $parser->parse($output);
+
+                foreach ($parser->references as $row) {
+                    list($commitHash, $fullname) = $row;
+                }
+
+                return $this->repository->getCommit($commitHash);
+            } catch (ProcessException $e) {
+                // ignore the exception
+            }
+        }
+
+        return parent::getCommit();
+    }
+
     /**
      * Returns the tagger name.
      *

tests/Gitonomy/Git/Tests/ReferenceTest.php

@@ -97,6 +97,13 @@ public function testAnnotatedTag($repository)
 
         $this->assertEquals('heading', $tag->getSubjectMessage(), 'Message heading is correct');
         $this->assertEquals("body\nbody", $tag->getBodyMessage(), 'Message body is correct');
+
+        $closure = function () {
+            return parent::getCommit();
+        };
+        $parentCommit = $closure->bindTo($tag, Tag::class);
+        $this->assertNotEquals($parentCommit()->getHash(), $tag->getCommit()->getHash(), 'Tag commit is not the same as main commit');
+        $this->assertEquals('fbde681b329a39e08b63dc54b341a3274c0380c0', $tag->getCommit()->getHash(), 'Tag commit is correct');
     }
 
     /**