From e3bb744195a5a9ffed1a0e377627a30fff483c76 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Tobias=20Nie=C3=9Fen?= <tniessen@tnie.de>
Date: Wed, 6 Jun 2018 17:11:54 +0200
Subject: [PATCH] Fix behavior of Commit#parent

Commit#parent did not assign the repo property so subsequent calls which
relied on this property (such as Commit#getTree) failed. This change
works around this problem by imitating what LookupWrapper does for
Commit.lookup, that is, it wraps the actual call in a new function and
manually assigns the repo property.
---
 lib/commit.js        | 18 ++++++++++++++++++
 test/tests/commit.js | 10 ++++++++++
 2 files changed, 28 insertions(+)

diff --git a/lib/commit.js b/lib/commit.js
index 033ecdfa1..c91245f04 100644
--- a/lib/commit.js
+++ b/lib/commit.js
@@ -16,6 +16,24 @@ var _parent = Commit.prototype.parent;
  */
 Commit.lookup = LookupWrapper(Commit);
 
+/**
+ * @async
+ * @param {Number} n
+ * @return {Commit}
+ */
+Commit.prototype.parent = function(n, callback) {
+  var repo = this.repo;
+  return _parent.call(this, n).then(p => {
+    p.repo = repo;
+
+    if (typeof callback === "function") {
+      callback(null, p);
+    }
+
+    return p;
+  }, callback);
+};
+
 /**
  * Amend a commit
  * @async
diff --git a/test/tests/commit.js b/test/tests/commit.js
index 237471923..69868333c 100644
--- a/test/tests/commit.js
+++ b/test/tests/commit.js
@@ -774,6 +774,16 @@ describe("Commit", function() {
     assert.equal(1, this.commit.parentcount());
   });
 
+  it("can fetch a single parent", function() {
+    return this.commit.parent(0).then(function(parent) {
+      assert.strictEqual(parent.sha(),
+                         "ecfd36c80a3e9081f200dfda2391acadb56dac27");
+      // This used to crash due to a missing .repo property on the retrieved
+      // parent.
+      return parent.getTree().then(tree => assert(tree));
+    });
+  });
+
   it("can retrieve and walk a commit tree", function() {
     var commitTreeEntryCount = 0;
     var expectedCommitTreeEntryCount = 198;