Fix bad postdecrement of NodeSet iterator

diff --git a/lib/vpsc/generate-constraints.cpp b/lib/vpsc/generate-constraints.cpp
index 8d0c9365ddfba4c76fb5093b4ebffb5eb7b974da..e40b58df3a2579799e7df389039a06ac72df4a9d 100644 (file)
--- a/lib/vpsc/generate-constraints.cpp
+++ b/lib/vpsc/generate-constraints.cpp
@@ -87,8 +87,8 @@ bool CmpNodePos::operator() (const Node* u, const Node* v) const {
 NodeSet* getLeftNeighbours(NodeSet &scanline,Node *v) {
        NodeSet *leftv = new NodeSet;
        NodeSet::iterator i=scanline.find(v);
-       while(i--!=scanline.begin()) {
-               Node *u=*(i);
+       while(i!=scanline.begin()) {
+               Node *u=*(--i);
                if(u->r->overlapX(v->r)<=0) {
                        leftv->insert(u);
                        return leftv;
@@ -169,8 +169,8 @@ int generateXConstraints(const int n, Rectangle** rs, Variable** vars, Constrain
                                );
                        } else {
                                NodeSet::iterator it=scanline.find(v);
-                               if(it--!=scanline.begin()) {
-                                       Node *u=*it;
+                               if(it!=scanline.begin()) {
+                                       Node *u=*--it;
                                        v->firstAbove=u;
                                        u->firstBelow=v;
                                }
@@ -247,8 +247,8 @@ int generateYConstraints(const int n, Rectangle** rs, Variable** vars, Constrain
                if(e->type==Open) {
                        scanline.insert(v);
                        NodeSet::iterator i=scanline.find(v);
-                       if(i--!=scanline.begin()) {
-                               Node *u=*i;
+                       if(i!=scanline.begin()) {
+                               Node *u=*--i;
                                v->firstAbove=u;
                                u->firstBelow=v;
                        }