From 0e9336be3f590b900a28a48b265dd2eab7836e03 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Carlos=20Mart=C3=ADn=20Nieto?= <cmn@dwim.me>
Date: Fri, 7 Jul 2017 23:36:04 +0200
Subject: [PATCH] commit: add keep-alives for those that need conversion to
 pointer receivers

We can't work on the copies here, we need to have pointer receivers so we know
we're keeping alive the object whose finalizer would free the unmanaged memory
we're working with.
---
 commit.go | 43 ++++++++++++++++++++++++++++---------------
 1 file changed, 28 insertions(+), 15 deletions(-)

diff --git a/commit.go b/commit.go
index fc04e1e..3ccb5da 100644
--- a/commit.go
+++ b/commit.go
@@ -18,15 +18,19 @@ type Commit struct {
 	cast_ptr *C.git_commit
 }
 
-func (c Commit) Message() string {
-	return C.GoString(C.git_commit_message(c.cast_ptr))
+func (c *Commit) Message() string {
+	ret := C.GoString(C.git_commit_message(c.cast_ptr))
+	runtime.KeepAlive(c)
+	return ret
 }
 
-func (c Commit) RawMessage() string {
-	return C.GoString(C.git_commit_message_raw(c.cast_ptr))
+func (c *Commit) RawMessage() string {
+	ret := C.GoString(C.git_commit_message_raw(c.cast_ptr))
+	runtime.KeepAlive(c)
+	return ret
 }
 
-func (c Commit) ExtractSignature() (string, string, error) {
+func (c *Commit) ExtractSignature() (string, string, error) {
 
 	var c_signed C.git_buf
 	defer C.git_buf_free(&c_signed)
@@ -40,7 +44,7 @@ func (c Commit) ExtractSignature() (string, string, error) {
 	runtime.LockOSThread()
 	defer runtime.UnlockOSThread()
 	ret := C.git_commit_extract_signature(&c_signature, &c_signed, repo, oid.toC(), nil)
-
+	runtime.KeepAlive(oid)
 	if ret < 0 {
 		return "", "", MakeGitError(ret)
 	} else {
@@ -49,17 +53,20 @@ func (c Commit) ExtractSignature() (string, string, error) {
 
 }
 
-func (c Commit) Summary() string {
-	return C.GoString(C.git_commit_summary(c.cast_ptr))
+func (c *Commit) Summary() string {
+	ret := C.GoString(C.git_commit_summary(c.cast_ptr))
+	runtime.KeepAlive(c)
+	return ret
 }
 
-func (c Commit) Tree() (*Tree, error) {
+func (c *Commit) Tree() (*Tree, error) {
 	var ptr *C.git_tree
 
 	runtime.LockOSThread()
 	defer runtime.UnlockOSThread()
 
 	err := C.git_commit_tree(&ptr, c.cast_ptr)
+	runtime.KeepAlive(c)
 	if err < 0 {
 		return nil, MakeGitError(err)
 	}
@@ -67,18 +74,24 @@ func (c Commit) Tree() (*Tree, error) {
 	return allocTree(ptr, c.repo), nil
 }
 
-func (c Commit) TreeId() *Oid {
-	return newOidFromC(C.git_commit_tree_id(c.cast_ptr))
+func (c *Commit) TreeId() *Oid {
+	ret := newOidFromC(C.git_commit_tree_id(c.cast_ptr))
+	runtime.KeepAlive(c)
+	return c
 }
 
-func (c Commit) Author() *Signature {
+func (c *Commit) Author() *Signature {
 	cast_ptr := C.git_commit_author(c.cast_ptr)
-	return newSignatureFromC(cast_ptr)
+	ret := newSignatureFromC(cast_ptr)
+	runtime.KeepAlive(c)
+	return ret
 }
 
-func (c Commit) Committer() *Signature {
+func (c *Commit) Committer() *Signature {
 	cast_ptr := C.git_commit_committer(c.cast_ptr)
-	return newSignatureFromC(cast_ptr)
+	ret := newSignatureFromC(cast_ptr)
+	runtime.KeepAlive(c)
+	return ret
 }
 
 func (c *Commit) Parent(n uint) *Commit {