Work around Go 1.6's CGo pointer check
It depends heavily on the expression at the call site an whether it can
figure out whether we're using a slice or not, so provid an incantation
that does this.
diff --git a/blob.go b/blob.go
index 1a86e60..8b3e94f 100644
--- a/blob.go
+++ b/blob.go
@@ -37,15 +37,24 @@
defer runtime.UnlockOSThread()
var id C.git_oid
- var ptr unsafe.Pointer
+ var size C.size_t
+ // Go 1.6 added some increased checking of passing pointer to
+ // C, but its check depends on its expectations of waht we
+ // pass to the C function, so unless we take the address of
+ // its contents at the call site itself, it can fail when
+ // 'data' is a slice of a slice.
+ //
+ // When we're given an empty slice, create a dummy one where 0
+ // isn't out of bounds.
if len(data) > 0 {
- ptr = unsafe.Pointer(&data[0])
+ size = C.size_t(len(data))
} else {
- ptr = unsafe.Pointer(nil)
+ data = []byte{0}
+ size = C.size_t(0)
}
- ecode := C.git_blob_create_frombuffer(&id, repo.ptr, ptr, C.size_t(len(data)))
+ ecode := C.git_blob_create_frombuffer(&id, repo.ptr, unsafe.Pointer(&data[0]), size)
if ecode < 0 {
return nil, MakeGitError(ecode)
}
