opts.detect_rename = DIFF_DETECT_RENAME;
opts.rename_limit = merge_rename_limit >= 0 ? merge_rename_limit :
diff_rename_limit >= 0 ? diff_rename_limit :
opts.detect_rename = DIFF_DETECT_RENAME;
opts.rename_limit = merge_rename_limit >= 0 ? merge_rename_limit :
diff_rename_limit >= 0 ? diff_rename_limit :