api-credential.txt: document that helpers field is filled-in automatically

diff --git a/graph.c b/graph.c
index 7358416a72e855b406e026036cf61bcdd15e5142..7e0a099f8329757b24770ec6788bf83a8398d76d 100644 (file)
--- a/graph.c
+++ b/graph.c
@@ -194,8 +194,10 @@ static struct strbuf *diff_output_prefix_callback(struct diff_options *opt, void
        struct git_graph *graph = data;
        static struct strbuf msgbuf = STRBUF_INIT;
 
+       assert(opt);
        assert(graph);
 
+       opt->output_prefix_length = graph->width;
        strbuf_reset(&msgbuf);
        graph_padding_line(graph, &msgbuf);
        return &msgbuf;
@@ -245,6 +247,7 @@ struct git_graph *graph_init(struct rev_info *opt)
         */
        opt->diffopt.output_prefix = diff_output_prefix_callback;
        opt->diffopt.output_prefix_data = graph;
+       opt->diffopt.output_prefix_length = 0;
 
        return graph;
 }