Lock the OS thread when acessing errors

The library stores error information in thread-local storage, which
means we need to make sure that the Go runtime doesn't switch OS
threads between the time we call a function and th time we attempt to
retrieve the error information.

1 files changed, 4 insertions, 0 deletions

diff --git a/commit.go b/commit.go
index c633e2d..498669e 100644
--- a/commit.go
+++ b/commit.go
@@ -9,6 +9,7 @@ extern int _go_git_treewalk(git_tree *tree, git_treewalk_mode mode, void *ptr);
 import "C"
 
 import (
+	"runtime"
 	"time"
 	"unsafe"
 )
@@ -25,6 +26,9 @@ func (c Commit) Message() string {
 func (c Commit) Tree() (*Tree, error) {
 	var ptr *C.git_object
 
+	runtime.LockOSThread()
+	defer runtime.UnlockOSThread()
+
 	err := C.git_commit_tree(&ptr, c.ptr)
 	if err < 0 {
 		return nil, LastError()