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, 7 insertions, 0 deletions

diff --git a/index.go b/index.go
index 4a69c1e..ac5148c 100644
--- a/index.go
+++ b/index.go
@@ -24,6 +24,9 @@ func (v *Index) AddByPath(path string) error {
 	cstr := C.CString(path)
 	defer C.free(unsafe.Pointer(cstr))
 
+	runtime.LockOSThread()
+	defer runtime.UnlockOSThread()
+
 	ret := C.git_index_add_bypath(v.ptr, cstr)
 	if ret < 0 {
 		return LastError()
@@ -34,6 +37,10 @@ func (v *Index) AddByPath(path string) error {
 
 func (v *Index) WriteTree() (*Oid, error) {
 	oid := new(Oid)
+
+	runtime.LockOSThread()
+	defer runtime.UnlockOSThread()
+
 	ret := C.git_index_write_tree(oid.toC(), v.ptr)
 	if ret < 0 {
 		return nil, LastError()