Merge branch 'mh/replace-refs'

Add an environment variable to tell Git to look into refs hierarchy
other than refs/replace/ for the object replacement data.

* mh/replace-refs:
  Allow to control where the replace refs are looked for

log-tree.c

diff --git a/log-tree.c b/log-tree.c
index 01beb11..e2f6de7 100644
--- a/log-tree.c
+++ b/log-tree.c
@@ -97,11 +97,12 @@
 
 	assert(cb_data == NULL);
 
-	if (starts_with(refname, "refs/replace/")) {
+	if (starts_with(refname, git_replace_ref_base)) {
 		struct object_id original_oid;
 		if (!check_replace_refs)
 			return 0;
-		if (get_oid_hex(refname + 13, &original_oid)) {
+		if (get_oid_hex(refname + strlen(git_replace_ref_base),
+				&original_oid)) {
 			warning("invalid replace ref %s", refname);
 			return 0;
 		}