Change signature of rank to allow it to report being given an unconnected graph

diff --git a/lib/common/ns.c b/lib/common/ns.c
index 87760132740e2ad8f0d0be5b470bf7287579be90..ef373ec2a92c8c96582efaf6dd3e1983f682b75a 100644 (file)
--- a/lib/common/ns.c
+++ b/lib/common/ns.c
@@ -298,7 +298,7 @@ static void init_cutvalues(void)
     dfs_cutval(GD_nlist(G), NULL);
 }
 
-static void feasible_tree(void)
+static int feasible_tree(void)
 {
     int i, delta;
     node_t *n;
@@ -337,10 +337,11 @@ static void feasible_tree(void)
                    fprintf(stderr, "\t%s\n", n->name);
            }
 #endif
-           abort();
+           return 1;
        }
     }
     init_cutvalues();
+    return 0;
 }
 
 /* walk up from v to LCA(v,w), setting new cutvalues. */
@@ -565,8 +566,10 @@ static int init_graph(graph_t * g)
  *   Out and in edges lists stored in ND_out and ND_in, even if the node
  *  doesn't have any out or in edges.
  * The node rank values are stored in ND_rank.
+ * Returns 0 if successful; returns 1 if not, the latter indicating that
+ * the graph was not connected.
  */
-void rank(graph_t * g, int balance, int maxiter)
+int rank(graph_t * g, int balance, int maxiter)
 {
     int iter = 0, feasible;
     char *s, *ns = "network simplex: ";
@@ -585,7 +588,7 @@ void rank(graph_t * g, int balance, int maxiter)
     else
        Search_size = SEARCHSIZE;
 
-    feasible_tree();
+    if (feasible_tree()) return 1;
     while ((e = leave_edge())) {
        f = enter_edge(e);
        update(e, f);
@@ -617,6 +620,7 @@ void rank(graph_t * g, int balance, int maxiter)
        fprintf(stderr, "%s%d nodes %d edges %d iter %.2f sec\n",
                ns, N_nodes, N_edges, iter, elapsed_sec());
     }
+    return 0;
 }
 
 /* set cut value of f, assuming values of edges on one side were already set */

diff --git a/lib/common/renderprocs.h b/lib/common/renderprocs.h
index 868ce396a830925dbdba67573f951fb6519f2cba..040efc71d00ec6d4944baf9c8eecd4914f168b3d 100644 (file)
--- a/lib/common/renderprocs.h
+++ b/lib/common/renderprocs.h
@@ -144,7 +144,7 @@ extern "C" {
     extern point pointof(int, int);
     extern int processClusterEdges(graph_t * g);
     extern char *ps_string(char *s);
-    extern void rank(graph_t * g, int balance, int maxiter);
+    extern int rank(graph_t * g, int balance, int maxiter);
     extern void routesplinesinit(void);
     extern point *routesplines(path *, int *);
     extern void routesplinesterm(void);