Fix code not to do malloc(0); short-circuit when component has only

a single node

diff --git a/lib/neatogen/constrained_majorization.c b/lib/neatogen/constrained_majorization.c
index 9d948aaa81cec781b0cdd69af8647e93e9139695..6a0f05b15997a3bbf123d6c5b0bf80c605d73134 100644 (file)
--- a/lib/neatogen/constrained_majorization.c
+++ b/lib/neatogen/constrained_majorization.c
@@ -141,11 +141,12 @@ stress_majorization_with_hierarchy(
                if (dim==2) {
                        IMDS_given_dim(graph, n, y, x, Epsilon);
                }
-       }       
+       }
        else {
         initLayout(graph, n, dim, d_coords);
                hierarchy_spread = compute_hierarchy(graph, n, abs_tol, relative_tol, NULL, &ordering, &levels, &num_levels);           
        }
+    if (n == 1) return 0;
 
        hierarchy_boundaries = N_GNEW(num_levels, float);
 

diff --git a/lib/neatogen/dijkstra.c b/lib/neatogen/dijkstra.c
index 29858cbbda418baec29a113a78bfee39ffb6c25b..5d37ec0f346844bd92ceb179c54992e6e6ae8ab8 100644 (file)
--- a/lib/neatogen/dijkstra.c
+++ b/lib/neatogen/dijkstra.c
@@ -80,24 +80,31 @@ static void heapify(heap * h, int i, int index[], Word dist[])
     }
 }
 
+#ifdef OBSOLETE
+/* originally, the code called mkHeap to allocate space, then
+ * initHeap to realloc the space. This is silly.
+ * Now we just call initHeap.
+ */
 static void mkHeap(heap * h, int size)
 {
     h->data = N_GNEW(size, int);
     h->heapSize = 0;
 }
+#endif
 
 static void freeHeap(heap * h)
 {
-    free(h->data);
+    if (h->data) free(h->data);
 }
 
 static void
 initHeap(heap * h, int startVertex, int index[], Word dist[], int n)
 {
     int i, count;
-    int j;                     /* We cannot use an unsigned value in this loop */
+    int j;    /* We cannot use an unsigned value in this loop */
     /* h->data=(int*) realloc(h->data, (n-1)*sizeof(int)); */
-    h->data = N_GNEW(n - 1, int);
+    if (n == 1) h->data = NULL;
+    else h->data = N_GNEW(n - 1, int);
     h->heapSize = n - 1;
 
     for (count = 0, i = 0; i < n; i++)
@@ -156,7 +163,9 @@ void dijkstra(int vertex, vtx_data * graph, int n, DistType * dist)
     DistType closestDist, prevClosestDist = MAXINT;
     static int *index;
 
+#ifdef OBSOLETE
     mkHeap(&H, n);
+#endif
     index = (int *) realloc(index, n * sizeof(int));
 
     /* initial distances with edge weights: */
@@ -229,7 +238,9 @@ dijkstra_bounded(int vertex, vtx_data * graph, int n, DistType * dist,
     }
 
 
+#ifdef OBSOLETE
     mkHeap(&H, n);
+#endif
     index = (int *) realloc(index, n * sizeof(int));
 
     /* initial distances with edge weights: */
@@ -239,7 +250,8 @@ dijkstra_bounded(int vertex, vtx_data * graph, int n, DistType * dist,
     for (i = 1; i < graph[vertex].nedges; i++)
        dist[graph[vertex].edges[i]] = (DistType) graph[vertex].ewgts[i];
 
-    initHeap(&H, vertex, index, dist, n);      /* again, TOO COSTLY (O(n)) to put all nodes in heap! */
+    /* again, TOO COSTLY (O(n)) to put all nodes in heap! */
+    initHeap(&H, vertex, index, dist, n); 
 
     while (num_found < num_visited_nodes
           && extractMax(&H, &closestVertex, index, dist)) {
@@ -356,7 +368,9 @@ void dijkstra_f(int vertex, vtx_data * graph, int n, float *dist)
     float closestDist;
     int *index;
 
+#ifdef OBSOLETE
     mkHeap(&H, n);
+#endif
     index = N_GNEW(n, int);
 
     /* initial distances with edge weights: */

diff --git a/lib/neatogen/stress.c b/lib/neatogen/stress.c
index a44c38a5f770713a6c7d40b5f8198da4da638cd9..cc2f1a85d3ada8d602c804e85f3550359beb38e6 100644 (file)
--- a/lib/neatogen/stress.c
+++ b/lib/neatogen/stress.c
@@ -1583,6 +1583,7 @@ int stress_majorization_kD_mkernel(vtx_data * graph,      /* Input graph in sparse re
     } else {
        havePinned = initLayout(graph, n, dim, d_coords);
     }
+    if (n == 1) return 0;
 
     if (Verbose) {
        fprintf(stderr, ": %.2f sec\n", elapsed_sec());