Make the rev graph visualization have a one rev look-ahead

diff --git a/tig.c b/tig.c
index f3109f6..34a6358 100644 (file)
--- a/tig.c
+++ b/tig.c
@@ -2694,13 +2694,14 @@ struct rev_graph {
 };
 
 /* Parents of the commit being visualized. */
-static struct rev_graph graph_parents[3];
+static struct rev_graph graph_parents[4];
 
 /* The current stack of revisions on the graph. */
-static struct rev_graph graph_stacks[3] = {
-       { &graph_stacks[2], &graph_stacks[1], &graph_parents[0] },
+static struct rev_graph graph_stacks[4] = {
+       { &graph_stacks[3], &graph_stacks[1], &graph_parents[0] },
        { &graph_stacks[0], &graph_stacks[2], &graph_parents[1] },
-       { &graph_stacks[1], &graph_stacks[0], &graph_parents[2] },
+       { &graph_stacks[1], &graph_stacks[3], &graph_parents[2] },
+       { &graph_stacks[2], &graph_stacks[0], &graph_parents[3] },
 };
 
 static inline bool
@@ -2850,7 +2851,14 @@ prepare_rev_graph(struct rev_graph *graph)
 static void
 update_rev_graph(struct rev_graph *graph)
 {
-       prepare_rev_graph(graph);
+       /* If this is the finalizing update ... */
+       if (graph->commit)
+               prepare_rev_graph(graph);
+
+       /* Graph visualization needs a one rev look-ahead,
+        * so the first update doesn't visualize anything. */
+       if (!graph->prev->commit)
+               return;
 
        draw_rev_graph(graph->prev);
        done_rev_graph(graph->prev->prev);
@@ -2979,6 +2987,7 @@ main_read(struct view *view, char *line)
                              ? view->line[view->lines - 1].data : NULL;
 
        if (!line) {
+               update_rev_graph(graph);
                return TRUE;
        }