From cbfd0c5005523b131449c6fdd7fa0c0bc84012a9 Mon Sep 17 00:00:00 2001 From: Aditya Sirish Date: Wed, 27 Sep 2023 11:54:31 -0400 Subject: plumbing/object: Support mergetag in merge commits When a merge commit is created from merging a signed tag, the tag object is embedded in the commit object. This commit adds support for this tag data when encoding and decoding a commit object. Signed-off-by: Aditya Sirish --- plumbing/object/commit.go | 38 +++++++++++++++++++++++++++++++++++ plumbing/object/commit_test.go | 45 ++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 83 insertions(+) diff --git a/plumbing/object/commit.go b/plumbing/object/commit.go index 8a0f35c..508e93c 100644 --- a/plumbing/object/commit.go +++ b/plumbing/object/commit.go @@ -20,6 +20,11 @@ const ( beginpgp string = "-----BEGIN PGP SIGNATURE-----" endpgp string = "-----END PGP SIGNATURE-----" headerpgp string = "gpgsig" + + // https://github.com/git/git/blob/bcb6cae2966cc407ca1afc77413b3ef11103c175/Documentation/gitformat-signature.txt#L153 + // When a merge commit is created from a signed tag, the tag is embedded in + // the commit with the "mergetag" header. + headermergetag string = "mergetag" ) // Hash represents the hash of an object @@ -38,6 +43,9 @@ type Commit struct { // Committer is the one performing the commit, might be different from // Author. Committer Signature + // MergeTag is the embedded tag object when a merge commit is created by + // merging a signed tag. + MergeTag string // PGPSignature is the PGP signature of the commit. PGPSignature string // Message is the commit message, contains arbitrary text. @@ -184,6 +192,7 @@ func (c *Commit) Decode(o plumbing.EncodedObject) (err error) { defer sync.PutBufioReader(r) var message bool + var mergetag bool var pgpsig bool var msgbuf bytes.Buffer for { @@ -192,6 +201,16 @@ func (c *Commit) Decode(o plumbing.EncodedObject) (err error) { return err } + if mergetag { + if len(line) > 0 && line[0] == ' ' { + line = bytes.TrimLeft(line, " ") + c.MergeTag += string(line) + continue + } else { + mergetag = false + } + } + if pgpsig { if len(line) > 0 && line[0] == ' ' { line = bytes.TrimLeft(line, " ") @@ -225,6 +244,9 @@ func (c *Commit) Decode(o plumbing.EncodedObject) (err error) { c.Author.Decode(data) case "committer": c.Committer.Decode(data) + case headermergetag: + c.MergeTag += string(data) + "\n" + mergetag = true case headerpgp: c.PGPSignature += string(data) + "\n" pgpsig = true @@ -286,6 +308,22 @@ func (c *Commit) encode(o plumbing.EncodedObject, includeSig bool) (err error) { return err } + if c.MergeTag != "" { + if _, err = fmt.Fprint(w, "\n"+headermergetag+" "); err != nil { + return err + } + + // Split tag information lines and re-write with a left padding and + // newline. Use join for this so it's clear that a newline should not be + // added after this section. The newline will be added either as part of + // the PGP signature or the commit message. + mergetag := strings.TrimSuffix(c.MergeTag, "\n") + lines := strings.Split(mergetag, "\n") + if _, err = fmt.Fprint(w, strings.Join(lines, "\n ")); err != nil { + return err + } + } + if c.PGPSignature != "" && includeSig { if _, err = fmt.Fprint(w, "\n"+headerpgp+" "); err != nil { return err diff --git a/plumbing/object/commit_test.go b/plumbing/object/commit_test.go index 4b0f6b4..f1a3447 100644 --- a/plumbing/object/commit_test.go +++ b/plumbing/object/commit_test.go @@ -3,6 +3,7 @@ package object import ( "bytes" "context" + "fmt" "io" "strings" "time" @@ -197,6 +198,27 @@ func (s *SuiteCommit) TestPatchContext_ToNil(c *C) { } func (s *SuiteCommit) TestCommitEncodeDecodeIdempotent(c *C) { + pgpsignature := `-----BEGIN PGP SIGNATURE----- + +iQEcBAABAgAGBQJTZbQlAAoJEF0+sviABDDrZbQH/09PfE51KPVPlanr6q1v4/Ut +LQxfojUWiLQdg2ESJItkcuweYg+kc3HCyFejeDIBw9dpXt00rY26p05qrpnG+85b +hM1/PswpPLuBSr+oCIDj5GMC2r2iEKsfv2fJbNW8iWAXVLoWZRF8B0MfqX/YTMbm +ecorc4iXzQu7tupRihslbNkfvfciMnSDeSvzCpWAHl7h8Wj6hhqePmLm9lAYqnKp +8S5B/1SSQuEAjRZgI4IexpZoeKGVDptPHxLLS38fozsyi0QyDyzEgJxcJQVMXxVi +RUysgqjcpT8+iQM1PblGfHR4XAhuOqN5Fx06PSaFZhqvWFezJ28/CLyX5q+oIVk= +=EFTF +-----END PGP SIGNATURE----- +` + + tag := fmt.Sprintf(`object f000000000000000000000000000000000000000 +type commit +tag change +tagger Foo 1695827841 -0400 + +change +%s +`, pgpsignature) + ts, err := time.Parse(time.RFC3339, "2006-01-02T15:04:05-07:00") c.Assert(err, IsNil) commits := []*Commit{ @@ -219,6 +241,29 @@ func (s *SuiteCommit) TestCommitEncodeDecodeIdempotent(c *C) { plumbing.NewHash("f000000000000000000000000000000000000007"), }, }, + { + Author: Signature{Name: "Foo", Email: "foo@example.local", When: ts}, + Committer: Signature{Name: "Bar", Email: "bar@example.local", When: ts}, + Message: "Testing mergetag\n\nHere, commit is not signed", + TreeHash: plumbing.NewHash("f000000000000000000000000000000000000001"), + ParentHashes: []plumbing.Hash{ + plumbing.NewHash("f000000000000000000000000000000000000002"), + plumbing.NewHash("f000000000000000000000000000000000000003"), + }, + MergeTag: tag, + }, + { + Author: Signature{Name: "Foo", Email: "foo@example.local", When: ts}, + Committer: Signature{Name: "Bar", Email: "bar@example.local", When: ts}, + Message: "Testing mergetag\n\nHere, commit is also signed", + TreeHash: plumbing.NewHash("f000000000000000000000000000000000000001"), + ParentHashes: []plumbing.Hash{ + plumbing.NewHash("f000000000000000000000000000000000000002"), + plumbing.NewHash("f000000000000000000000000000000000000003"), + }, + MergeTag: tag, + PGPSignature: pgpsignature, + }, } for _, commit := range commits { obj := &plumbing.MemoryObject{} -- cgit