Cherrypick

4 files changed, 164 insertions, 1 deletions

diff --git a/checkout.go b/checkout.go
index 72a1fe3..6eb6098 100644
--- a/checkout.go
+++ b/checkout.go
@@ -40,6 +40,19 @@ type CheckoutOpts struct {
 	TargetDirectory string           // Alternative checkout path to workdir
 }
 
+func checkoutOptionsFromC(c *C.git_checkout_options) CheckoutOpts {
+	opts := CheckoutOpts{}
+	opts.Strategy = CheckoutStrategy(c.checkout_strategy)
+	opts.DisableFilters = c.disable_filters != 0
+	opts.DirMode = os.FileMode(c.dir_mode)
+	opts.FileMode = os.FileMode(c.file_mode)
+	opts.FileOpenFlags = int(c.file_open_flags)
+	if c.target_directory != nil {
+		opts.TargetDirectory = C.GoString(c.target_directory)
+	}
+	return opts
+}
+
 func (opts *CheckoutOpts) toC() *C.git_checkout_options {
 	if opts == nil {
 		return nil
diff --git a/cherrypick.go b/cherrypick.go
new file mode 100644
index 0000000..afc1b7e
--- /dev/null
+++ b/cherrypick.go
@@ -0,0 +1,73 @@
+package git
+
+/*
+#include <git2.h>
+*/
+import "C"
+import (
+	"runtime"
+)
+
+type CherrypickOptions struct {
+	Version      uint
+	Mainline     uint
+	MergeOpts    MergeOptions
+	CheckoutOpts CheckoutOpts
+}
+
+func cherrypickOptionsFromC(c *C.git_cherrypick_options) CherrypickOptions {
+	opts := CherrypickOptions{
+		Version:      uint(c.version),
+		Mainline:     uint(c.mainline),
+		MergeOpts:    mergeOptionsFromC(&c.merge_opts),
+		CheckoutOpts: checkoutOptionsFromC(&c.checkout_opts),
+	}
+	return opts
+}
+
+func (opts *CherrypickOptions) toC() *C.git_cherrypick_options {
+	if opts == nil {
+		return nil
+	}
+	c := C.git_cherrypick_options{}
+	c.version = C.uint(opts.Version)
+	c.mainline = C.uint(opts.Mainline)
+	c.merge_opts = *opts.MergeOpts.toC()
+	c.checkout_opts = *opts.CheckoutOpts.toC()
+	return &c
+}
+
+func freeCherrypickOpts(ptr *C.git_cherrypick_options) {
+	if ptr == nil {
+		return
+	}
+	freeCheckoutOpts(&ptr.checkout_opts)
+}
+
+func DefaultCherrypickOptions() (CherrypickOptions, error) {
+	c := C.git_cherrypick_options{}
+
+	runtime.LockOSThread()
+	defer runtime.UnlockOSThread()
+
+	ecode := C.git_cherrypick_init_options(&c, C.GIT_CHERRYPICK_OPTIONS_VERSION)
+	if ecode < 0 {
+		return CherrypickOptions{}, MakeGitError(ecode)
+	}
+	defer freeCherrypickOpts(&c)
+	return cherrypickOptionsFromC(&c), nil
+}
+
+func (v *Repository) Cherrypick(commit *Commit, opts CherrypickOptions) error {
+	runtime.LockOSThread()
+	defer runtime.UnlockOSThread()
+
+	cOpts := opts.toC()
+	defer freeCherrypickOpts(cOpts)
+
+	ecode := C.git_cherrypick(v.ptr, commit.cast_ptr, cOpts)
+	if ecode < 0 {
+		return MakeGitError(ecode)
+	}
+	return nil
+}
diff --git a/cherrypick_test.go b/cherrypick_test.go
new file mode 100644
index 0000000..c867cf9
--- /dev/null
+++ b/cherrypick_test.go
@@ -0,0 +1,73 @@
+package git
+
+import (
+	"io/ioutil"
+	"testing"
+)
+
+func checkout(t *testing.T, repo *Repository, commit *Commit) {
+	tree, err := commit.Tree()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	err = repo.CheckoutTree(tree, &CheckoutOpts{Strategy: CheckoutSafe})
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	err = repo.SetHeadDetached(commit.Id(), commit.Author(), "checkout")
+	if err != nil {
+		t.Fatal(err)
+	}
+}
+
+const content = "Herro, Worrd!"
+
+func readReadme(t *testing.T, repo *Repository) string {
+	bytes, err := ioutil.ReadFile(pathInRepo(repo, "README"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	return string(bytes)
+}
+
+func TestCherrypick(t *testing.T) {
+	repo := createTestRepo(t)
+	c1, _ := seedTestRepo(t, repo)
+	c2, _ := updateReadme(t, repo, content)
+
+	commit1, err := repo.LookupCommit(c1)
+	if err != nil {
+		t.Fatal(err)
+	}
+	commit2, err := repo.LookupCommit(c2)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	checkout(t, repo, commit1)
+
+	if readReadme(t, repo) == content {
+		t.Fatalf("README has wrong content after checking out initial commit")
+	}
+
+	opts, err := DefaultCherrypickOptions()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	err = repo.Cherrypick(commit2, opts)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if readReadme(t, repo) != content {
+		t.Fatalf("README has wrong contents after cherry-picking")
+	}
+
+	state := repo.State()
+	if state != RepositoryStateCherrypick {
+		t.Fatal("Incorrect repository state: ", state)
+	}
+}
diff --git a/git_test.go b/git_test.go
index 56adeed..b9cf0a9 100644
--- a/git_test.go
+++ b/git_test.go
@@ -57,6 +57,10 @@ func seedTestRepo(t *testing.T, repo *Repository) (*Oid, *Oid) {
 	return commitId, treeId
 }
 
+func pathInRepo(repo *Repository, name string) string {
+	return path.Join(path.Dir(path.Dir(repo.Path())), name)
+}
+
 func updateReadme(t *testing.T, repo *Repository, content string) (*Oid, *Oid) {
 	loc, err := time.LoadLocation("Europe/Berlin")
 	checkFatal(t, err)
@@ -67,7 +71,7 @@ func updateReadme(t *testing.T, repo *Repository, content string) (*Oid, *Oid) {
 	}
 
 	tmpfile := "README"
-	err = ioutil.WriteFile(path.Join(path.Dir(path.Dir(repo.Path())), tmpfile), []byte(content), 0644)
+	err = ioutil.WriteFile(pathInRepo(repo, tmpfile), []byte(content), 0644)
 	checkFatal(t, err)
 
 	idx, err := repo.Index()