From 6b797242d6ddd149d3e6a8d8496c6e442541b7ae Mon Sep 17 00:00:00 2001
From: Arieh Schneier <15041913+AriehSchneier@users.noreply.github.com>
Date: Mon, 29 Jul 2024 11:56:26 +1000
Subject: git: Fix fetching missing commits

Signed-off-by: Arieh Schneier <15041913+AriehSchneier@users.noreply.github.com>
---
 remote.go      | 27 +++++++++++++++++----------
 remote_test.go | 44 +++++++++++++++++++++++++++++++++++++++++---
 2 files changed, 58 insertions(+), 13 deletions(-)

diff --git a/remote.go b/remote.go
index 7cc0db9..170883a 100644
--- a/remote.go
+++ b/remote.go
@@ -9,6 +9,7 @@ import (
 	"time"
 
 	"github.com/go-git/go-billy/v5/osfs"
+
 	"github.com/go-git/go-git/v5/config"
 	"github.com/go-git/go-git/v5/internal/url"
 	"github.com/go-git/go-git/v5/plumbing"
@@ -491,7 +492,18 @@ func (r *Remote) fetch(ctx context.Context, o *FetchOptions) (sto storer.Referen
 	}
 
 	if !updated && !updatedPrune {
-		return remoteRefs, NoErrAlreadyUpToDate
+		// No references updated, but may have fetched new objects, check if we now have any of our wants
+		for _, hash := range req.Wants {
+			exists, _ := objectExists(r.s, hash)
+			if exists {
+				updated = true
+				break
+			}
+		}
+
+		if !updated {
+			return remoteRefs, NoErrAlreadyUpToDate
+		}
 	}
 
 	return remoteRefs, nil
@@ -878,17 +890,12 @@ func getHavesFromRef(
 		return nil
 	}
 
-	// No need to load the commit if we know the remote already
-	// has this hash.
-	if remoteRefs[h] {
-		haves[h] = true
-		return nil
-	}
-
 	commit, err := object.GetCommit(s, h)
 	if err != nil {
-		// Ignore the error if this isn't a commit.
-		haves[ref.Hash()] = true
+		if !errors.Is(err, plumbing.ErrObjectNotFound) {
+			// Ignore the error if this isn't a commit.
+			haves[ref.Hash()] = true
+		}
 		return nil
 	}
 
diff --git a/remote_test.go b/remote_test.go
index d1439d5..c816cc5 100644
--- a/remote_test.go
+++ b/remote_test.go
@@ -14,6 +14,9 @@ import (
 	"time"
 
 	"github.com/go-git/go-billy/v5/memfs"
+	"github.com/go-git/go-billy/v5/osfs"
+	"github.com/go-git/go-billy/v5/util"
+
 	"github.com/go-git/go-git/v5/config"
 	"github.com/go-git/go-git/v5/plumbing"
 	"github.com/go-git/go-git/v5/plumbing/cache"
@@ -346,6 +349,38 @@ func (s *RemoteSuite) testFetch(c *C, r *Remote, o *FetchOptions, expected []*pl
 	}
 }
 
+func (s *RemoteSuite) TestFetchOfMissingObjects(c *C) {
+	tmp, clean := s.TemporalDir()
+	defer clean()
+
+	// clone to a local temp folder
+	_, err := PlainClone(tmp, true, &CloneOptions{
+		URL: fixtures.Basic().One().DotGit().Root(),
+	})
+	c.Assert(err, IsNil)
+
+	// Delete the pack files
+	fsTmp := osfs.New(tmp)
+	err = util.RemoveAll(fsTmp, "objects/pack")
+	c.Assert(err, IsNil)
+
+	// Reopen the repo from the filesystem (with missing objects)
+	r, err := Open(filesystem.NewStorage(fsTmp, cache.NewObjectLRUDefault()), nil)
+	c.Assert(err, IsNil)
+
+	// Confirm we are missing a commit
+	_, err = r.CommitObject(plumbing.NewHash("6ecf0ef2c2dffb796033e5a02219af86ec6584e5"))
+	c.Assert(err, Equals, plumbing.ErrObjectNotFound)
+
+	// Refetch to get all the missing objects
+	err = r.Fetch(&FetchOptions{})
+	c.Assert(err, IsNil)
+
+	// Confirm we now have the commit
+	_, err = r.CommitObject(plumbing.NewHash("6ecf0ef2c2dffb796033e5a02219af86ec6584e5"))
+	c.Assert(err, IsNil)
+}
+
 func (s *RemoteSuite) TestFetchWithProgress(c *C) {
 	url := s.GetBasicLocalRepositoryURL()
 	sto := memory.NewStorage()
@@ -1220,17 +1255,20 @@ func (s *RemoteSuite) TestGetHaves(c *C) {
 	sto := filesystem.NewStorage(f.DotGit(), cache.NewObjectLRUDefault())
 
 	var localRefs = []*plumbing.Reference{
+		// Exists
 		plumbing.NewReferenceFromStrings(
 			"foo",
-			"f7b877701fbf855b44c0a9e86f3fdce2c298b07f",
+			"b029517f6300c2da0f4b651b8642506cd6aaf45d",
 		),
+		// Exists
 		plumbing.NewReferenceFromStrings(
 			"bar",
-			"fe6cb94756faa81e5ed9240f9191b833db5f40ae",
+			"b8e471f58bcbca63b07bda20e428190409c2db47",
 		),
+		// Doesn't Exist
 		plumbing.NewReferenceFromStrings(
 			"qux",
-			"f7b877701fbf855b44c0a9e86f3fdce2c298b07f",
+			"0000000",
 		),
 	}
 
-- 
cgit