+static void graph_update_width(struct git_graph *graph,
+ int is_commit_in_existing_columns)
+{
+ /*
+ * Compute the width needed to display the graph for this commit.
+ * This is the maximum width needed for any row. All other rows
+ * will be padded to this width.
+ *
+ * Compute the number of columns in the widest row:
+ * Count each existing column (graph->num_columns), and each new
+ * column added by this commit.
+ */
+ int max_cols = graph->num_columns + graph->num_parents;
+
+ /*
+ * Even if the current commit has no parents, it still takes up a
+ * column for itself.
+ */
+ if (graph->num_parents < 1)
+ max_cols++;
+
+ /*
+ * We added a column for the the current commit as part of
+ * graph->num_parents. If the current commit was already in
+ * graph->columns, then we have double counted it.
+ */
+ if (is_commit_in_existing_columns)
+ max_cols--;
+
+ /*
+ * Each column takes up 2 spaces
+ */
+ graph->width = max_cols * 2;
+}
+