Fix commit retrieval by tag (#21804)

It is not correct to return tag data when commit data is requested, so
remove the hacky code that overwrote parts of a commit with parts of a
tag.

This fixes commit retrieval by tag for both the latest commit in the UI
and the commit info on tag webhook events.

Fixes: https://github.com/go-gitea/gitea/issues/21687
Replaces: https://github.com/go-gitea/gitea/pull/21693

<img width="324" alt="Screenshot 2022-11-13 at 15 26 37"
src="https://user-images.githubusercontent.com/115237/201526975-736c6ea7-ad6a-467a-a823-9a63d6ecb718.png">

<img width="789" alt="image"
src="https://user-images.githubusercontent.com/115237/201526876-90a13ffc-1e5c-4d76-911b-f1ae51e8eaab.png">

---------

Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

modules/git/repo_commit_gogit.go

@@ -7,7 +7,6 @@
 package git
 
 import (
-	"fmt"
 	"strings"
 
 	"github.com/go-git/go-git/v5/plumbing"
@@ -67,38 +66,6 @@ func (repo *Repository) IsCommitExist(name string) bool {
 	return err == nil
 }
 
-func convertPGPSignatureForTag(t *object.Tag) *CommitGPGSignature {
-	if t.PGPSignature == "" {
-		return nil
-	}
-
-	var w strings.Builder
-	var err error
-
-	if _, err = fmt.Fprintf(&w,
-		"object %s\ntype %s\ntag %s\ntagger ",
-		t.Target.String(), t.TargetType.Bytes(), t.Name); err != nil {
-		return nil
-	}
-
-	if err = t.Tagger.Encode(&w); err != nil {
-		return nil
-	}
-
-	if _, err = fmt.Fprintf(&w, "\n\n"); err != nil {
-		return nil
-	}
-
-	if _, err = fmt.Fprintf(&w, t.Message); err != nil {
-		return nil
-	}
-
-	return &CommitGPGSignature{
-		Signature: t.PGPSignature,
-		Payload:   strings.TrimSpace(w.String()) + "\n",
-	}
-}
-
 func (repo *Repository) getCommit(id SHA1) (*Commit, error) {
 	var tagObject *object.Tag
 
@@ -122,12 +89,6 @@ func (repo *Repository) getCommit(id SHA1) (*Commit, error) {
 	commit := convertCommit(gogitCommit)
 	commit.repo = repo
 
-	if tagObject != nil {
-		commit.CommitMessage = strings.TrimSpace(tagObject.Message)
-		commit.Author = &tagObject.Tagger
-		commit.Signature = convertPGPSignatureForTag(tagObject)
-	}
-
 	tree, err := gogitCommit.Tree()
 	if err != nil {
 		return nil, err

modules/git/repo_commit_nogogit.go

@@ -107,10 +107,6 @@ func (repo *Repository) getCommitFromBatchReader(rd *bufio.Reader, id SHA1) (*Co
 			return nil, err
 		}
 
-		commit.CommitMessage = strings.TrimSpace(tag.Message)
-		commit.Author = tag.Tagger
-		commit.Signature = tag.Signature
-
 		return commit, nil
 	case "commit":
 		commit, err := CommitFromReader(repo, id, io.LimitReader(rd, size))

modules/git/repo_commit_test.go

@@ -43,12 +43,13 @@ func TestGetTagCommitWithSignature(t *testing.T) {
 	assert.NoError(t, err)
 	defer bareRepo1.Close()
 
-	commit, err := bareRepo1.GetCommit("3ad28a9149a2864384548f3d17ed7f38014c9e8a")
+	// both the tag and the commit are signed here, this validates only the commit signature
+	commit, err := bareRepo1.GetCommit("28b55526e7100924d864dd89e35c1ea62e7a5a32")
 	assert.NoError(t, err)
 	assert.NotNil(t, commit)
 	assert.NotNil(t, commit.Signature)
 	// test that signature is not in message
-	assert.Equal(t, "tag", commit.CommitMessage)
+	assert.Equal(t, "signed-commit\n", commit.CommitMessage)
 }
 
 func TestGetCommitWithBadCommitID(t *testing.T) {

modules/git/repo_ref_test.go

@@ -19,13 +19,14 @@ func TestRepository_GetRefs(t *testing.T) {
 	refs, err := bareRepo1.GetRefs()
 
 	assert.NoError(t, err)
-	assert.Len(t, refs, 5)
+	assert.Len(t, refs, 6)
 
 	expectedRefs := []string{
 		BranchPrefix + "branch1",
 		BranchPrefix + "branch2",
 		BranchPrefix + "master",
 		TagPrefix + "test",
+		TagPrefix + "signed-tag",
 		NotesRef,
 	}
 
@@ -43,9 +44,12 @@ func TestRepository_GetRefsFiltered(t *testing.T) {
 	refs, err := bareRepo1.GetRefsFiltered(TagPrefix)
 
 	assert.NoError(t, err)
-	if assert.Len(t, refs, 1) {
-		assert.Equal(t, TagPrefix+"test", refs[0].Name)
+	if assert.Len(t, refs, 2) {
+		assert.Equal(t, TagPrefix+"signed-tag", refs[0].Name)
 		assert.Equal(t, "tag", refs[0].Type)
-		assert.Equal(t, "3ad28a9149a2864384548f3d17ed7f38014c9e8a", refs[0].Object.String())
+		assert.Equal(t, "36f97d9a96457e2bab511db30fe2db03893ebc64", refs[0].Object.String())
+		assert.Equal(t, TagPrefix+"test", refs[1].Name)
+		assert.Equal(t, "tag", refs[1].Type)
+		assert.Equal(t, "3ad28a9149a2864384548f3d17ed7f38014c9e8a", refs[1].Object.String())
 	}
 }

modules/git/repo_stats_test.go

@@ -24,9 +24,9 @@ func TestRepository_GetCodeActivityStats(t *testing.T) {
 	assert.NoError(t, err)
 	assert.NotNil(t, code)
 
-	assert.EqualValues(t, 9, code.CommitCount)
+	assert.EqualValues(t, 10, code.CommitCount)
 	assert.EqualValues(t, 3, code.AuthorCount)
-	assert.EqualValues(t, 9, code.CommitCountInAllBranches)
+	assert.EqualValues(t, 10, code.CommitCountInAllBranches)
 	assert.EqualValues(t, 10, code.Additions)
 	assert.EqualValues(t, 1, code.Deletions)
 	assert.Len(t, code.Authors, 3)

modules/git/repo_tag_test.go

@@ -25,11 +25,14 @@ func TestRepository_GetTags(t *testing.T) {
 		assert.NoError(t, err)
 		return
 	}
-	assert.Len(t, tags, 1)
+	assert.Len(t, tags, 2)
 	assert.Equal(t, len(tags), total)
-	assert.EqualValues(t, "test", tags[0].Name)
-	assert.EqualValues(t, "3ad28a9149a2864384548f3d17ed7f38014c9e8a", tags[0].ID.String())
+	assert.EqualValues(t, "signed-tag", tags[0].Name)
+	assert.EqualValues(t, "36f97d9a96457e2bab511db30fe2db03893ebc64", tags[0].ID.String())
 	assert.EqualValues(t, "tag", tags[0].Type)
+	assert.EqualValues(t, "test", tags[1].Name)
+	assert.EqualValues(t, "3ad28a9149a2864384548f3d17ed7f38014c9e8a", tags[1].ID.String())
+	assert.EqualValues(t, "tag", tags[1].Type)
 }
 
 func TestRepository_GetTag(t *testing.T) {

modules/git/repo_test.go

@@ -14,10 +14,10 @@ func TestGetLatestCommitTime(t *testing.T) {
 	bareRepo1Path := filepath.Join(testReposDir, "repo1_bare")
 	lct, err := GetLatestCommitTime(DefaultContext, bareRepo1Path)
 	assert.NoError(t, err)
-	// Time is Sun Jul 21 22:43:13 2019 +0200
+	// Time is Sun Nov 13 16:40:14 2022 +0100
 	// which is the time of commit
-	// feaf4ba6bc635fec442f46ddd4512416ec43c2c2 (refs/heads/master)
-	assert.EqualValues(t, 1563741793, lct.Unix())
+	// ce064814f4a0d337b333e646ece456cd39fab612 (refs/heads/master)
+	assert.EqualValues(t, 1668354014, lct.Unix())
 }
 
 func TestRepoIsEmpty(t *testing.T) {

modules/git/tests/repos/repo1_bare/logs/HEAD

@@ -1 +1,2 @@
 37991dec2c8e592043f47155ce4808d4580f9123 feaf4ba6bc635fec442f46ddd4512416ec43c2c2 silverwind <me@silverwind.io> 1563741799 +0200	push
+feaf4ba6bc635fec442f46ddd4512416ec43c2c2 ce064814f4a0d337b333e646ece456cd39fab612 silverwind <me@silverwind.io> 1668354026 +0100	push

modules/git/tests/repos/repo1_bare/logs/refs/heads/master

@@ -1 +1,2 @@
 37991dec2c8e592043f47155ce4808d4580f9123 feaf4ba6bc635fec442f46ddd4512416ec43c2c2 silverwind <me@silverwind.io> 1563741799 +0200	push
+feaf4ba6bc635fec442f46ddd4512416ec43c2c2 ce064814f4a0d337b333e646ece456cd39fab612 silverwind <me@silverwind.io> 1668354026 +0100	push

modules/git/tests/repos/repo1_bare/refs/heads/master

@@ -1 +1 @@
-feaf4ba6bc635fec442f46ddd4512416ec43c2c2
+ce064814f4a0d337b333e646ece456cd39fab612

modules/git/tests/repos/repo1_bare/refs/tags/signed-tag

@@ -0,0 +1 @@
+36f97d9a96457e2bab511db30fe2db03893ebc64