remove use of longjmp() in add_tree_edge()

This also fixes some resource leaks that occurred in this path. The longjmp()
would jump over some intermediate allocations that had been made, whereas we now
return back through the callers, cleaning up resources as we go. Related to
#1801.

diff --git a/lib/common/ns.c b/lib/common/ns.c
index 1cc03210e3a94e9ee861d292a5384c989c9a6326..5dc5a1df3cdfe65761c8a7c96d3b113cd34328be 100644 (file)
--- a/lib/common/ns.c
+++ b/lib/common/ns.c
@@ -48,7 +48,7 @@ static int add_tree_edge(edge_t * e)
     //fprintf(stderr,"add tree edge %p %s ", (void*)e, agnameof(agtail(e))) ; fprintf(stderr,"%s\n", agnameof(aghead(e))) ;
     if (TREE_EDGE(e)) {
        agerr(AGERR, "add_tree_edge: missing tree edge\n");
-       longjmp (jbuf, 1);
+       return -1;
     }
     ED_tree_index(e) = Tree_edge.size;
     Tree_edge.list[Tree_edge.size++] = e;
@@ -62,7 +62,7 @@ static int add_tree_edge(edge_t * e)
     ND_tree_out(n).list[ND_tree_out(n).size] = NULL;
     if (ND_out(n).list[ND_tree_out(n).size - 1] == 0) {
        agerr(AGERR, "add_tree_edge: empty outedge list\n");
-       longjmp (jbuf, 1);
+       return -1;
     }
     n = aghead(e);
     ND_mark(n) = TRUE;
@@ -70,7 +70,7 @@ static int add_tree_edge(edge_t * e)
     ND_tree_in(n).list[ND_tree_in(n).size] = NULL;
     if (ND_in(n).list[ND_tree_in(n).size - 1] == 0) {
        agerr(AGERR, "add_tree_edge: empty inedge list\n");
-       longjmp (jbuf, 1);
+       return -1;
     }
     return 0;
 }