Fix bug #680. Check that src/dest memcpy arguments are non-NULL.

src/maths/ni/niiter.c

@@ -246,6 +246,7 @@ NIiter(CKTcircuit *ckt, int maxIter)
                CKTnumStates the first time it is run */
             if (!OldCKTstate0)
                 OldCKTstate0 = TMALLOC(double, ckt->CKTnumStates + 1);
+            if (ckt->CKTstate0)
                 memcpy(OldCKTstate0, ckt->CKTstate0,
                        (size_t) ckt->CKTnumStates * sizeof(double));
 

src/spicelib/analysis/dctran.c

@@ -341,8 +341,10 @@ DCtran(CKTcircuit *ckt,
         ckt->CKTmode = (ckt->CKTmode&MODEUIC) | MODETRAN | MODEINITTRAN;
         /* modeinittran set here */
         ckt->CKTag[0]=ckt->CKTag[1]=0;
+        if (ckt->CKTstate1 && ckt->CKTstate0) {
             memcpy(ckt->CKTstate1, ckt->CKTstate0,
                   (size_t) ckt->CKTnumStates * sizeof(double));
+        }
 
 #ifdef WANT_SENSE2
         if(ckt->CKTsenInfo && (ckt->CKTsenInfo->SENmode & TRANSEN)){
@@ -790,7 +792,7 @@ resume:
 
         ckt->CKTstat->STATtimePts ++;
         ckt->CKTmode = (ckt->CKTmode&MODEUIC)|MODETRAN | MODEINITPRED;
-        if(firsttime) {
+        if(firsttime && ckt->CKTstate1 && ckt->CKTstate2 && ckt->CKTstate3) {
             memcpy(ckt->CKTstate2, ckt->CKTstate1,
                    (size_t) ckt->CKTnumStates * sizeof(double));
             memcpy(ckt->CKTstate3, ckt->CKTstate1,

src/spicelib/analysis/dctrcurv.c

@@ -456,9 +456,11 @@ DCtrCurv(CKTcircuit *ckt, int restart)
 
         if (firstTime) {
             firstTime = 0;
+            if (ckt->CKTstate1 && ckt->CKTstate0) {
                 memcpy(ckt->CKTstate1, ckt->CKTstate0,
                        (size_t) ckt->CKTnumStates * sizeof(double));
             }
+        }
 
         i = 0;