Merge branch 'js/rebase-stat-unrelated-fix'

"git rebase --stat" to transplant a piece of history onto a totally
unrelated history were not working before and silently showed wrong
result.  With the recent reimplementation in C, it started to instead
die with an error message, as the original logic was not prepared
to cope with this case.  This has now been fixed.

* js/rebase-stat-unrelated-fix:
  rebase --stat: fix when rebasing to an unrelated history

1 files changed, 12 insertions, 6 deletions

diff --git a/builtin/rebase.c b/builtin/rebase.c
index ba0c3c954b..c87da417fb 100644
--- a/builtin/rebase.c
+++ b/builtin/rebase.c
@@ -1503,10 +1503,15 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 	if (options.flags & REBASE_DIFFSTAT) {
 		struct diff_options opts;
 
-		if (options.flags & REBASE_VERBOSE)
-			printf(_("Changes from %s to %s:\n"),
-				oid_to_hex(&merge_base),
-				oid_to_hex(&options.onto->object.oid));
+		if (options.flags & REBASE_VERBOSE) {
+			if (is_null_oid(&merge_base))
+				printf(_("Changes to %s:\n"),
+				       oid_to_hex(&options.onto->object.oid));
+			else
+				printf(_("Changes from %s to %s:\n"),
+				       oid_to_hex(&merge_base),
+				       oid_to_hex(&options.onto->object.oid));
+		}
 
 		/* We want color (if set), but no pager */
 		diff_setup(&opts);
@@ -1516,8 +1521,9 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 			DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
 		opts.detect_rename = DIFF_DETECT_RENAME;
 		diff_setup_done(&opts);
-		diff_tree_oid(&merge_base, &options.onto->object.oid,
-			      "", &opts);
+		diff_tree_oid(is_null_oid(&merge_base) ?
+			      the_hash_algo->empty_tree : &merge_base,
+			      &options.onto->object.oid, "", &opts);
 		diffcore_std(&opts);
 		diff_flush(&opts);
 	}