check for shorted voltage sources, to avoid a segmentation fault

ChangeLog

@@ -1,3 +1,10 @@
+2010-08-15  Robert Larice
+ * src/spicelib/devices/asrc/asrcset.c ,
+ * src/spicelib/devices/ccvs/ccvsset.c ,
+ * src/spicelib/devices/vcvs/vcvsset.c ,
+ * src/spicelib/devices/vsrc/vsrcset.c :
+    check for shorted voltage sources, to avoid a segmentation fault
+
 2010-08-15  Robert Larice
  * src/maths/sparse/spdefs.h :
     fix txfree() prototype

src/spicelib/devices/asrc/asrcset.c

@@ -64,6 +64,13 @@ if((here->ptr = SMPmakeElt(matrix, here->first, (second)->number))\
 		return E_PARMVAL;
 
 	    if( here->ASRCtype == ASRC_VOLTAGE) {
+
+                if(here->ASRCposNode == here->ASRCnegNode) {
+                    (*(SPfrontEnd->IFerror))(ERR_FATAL,
+                              "instance %s is a shorted ASRC", &here->ASRCname);
+                    return(E_UNSUPP);
+                }
+
             	here->ASRCposptr = (double **)
             	  REALLOC(here->ASRCposptr, (sizeof(double *)*(j+5)));
             	TSTALLOC(ASRCposptr[j++],ASRCposNode,ASRCbranch);

src/spicelib/devices/ccvs/ccvsset.c

@@ -29,6 +29,12 @@ CCVSsetup(SMPmatrix *matrix, GENmodel *inModel, CKTcircuit *ckt, int *states)
         for (here = model->CCVSinstances; here != NULL ;
                 here=here->CCVSnextInstance) {
             
+            if(here->CCVSposNode == here->CCVSnegNode) {
+                (*(SPfrontEnd->IFerror))(ERR_FATAL,
+                        "instance %s is a shorted CCVS", &here->CCVSname);
+                return(E_UNSUPP);
+            }
+
             if(here->CCVSbranch==0) {
                 error = CKTmkCur(ckt,&tmp,here->CCVSname, "branch");
                 if(error) return(error);

src/spicelib/devices/vcvs/vcvsset.c

@@ -30,6 +30,12 @@ VCVSsetup(SMPmatrix *matrix, GENmodel *inModel, CKTcircuit *ckt, int *states)
         for (here = model->VCVSinstances; here != NULL ;
                 here=here->VCVSnextInstance) {
             
+            if(here->VCVSposNode == here->VCVSnegNode) {
+                (*(SPfrontEnd->IFerror))(ERR_FATAL,
+                        "instance %s is a shorted VCVS", &here->VCVSname);
+                return(E_UNSUPP);
+            }
+
             if(here->VCVSbranch == 0) {
                 error = CKTmkCur(ckt,&tmp,here->VCVSname,"branch");
                 if(error) return(error);

src/spicelib/devices/vsrc/vsrcset.c

@@ -29,6 +29,12 @@ VSRCsetup(SMPmatrix *matrix, GENmodel *inModel, CKTcircuit *ckt, int *state)
         for (here = model->VSRCinstances; here != NULL ;
                 here=here->VSRCnextInstance) {
             
+            if(here->VSRCposNode == here->VSRCnegNode) {
+                (*(SPfrontEnd->IFerror))(ERR_FATAL,
+                        "instance %s is a shorted VSRC", &here->VSRCname);
+                return(E_UNSUPP);
+            }
+
             if(here->VSRCbranch == 0) {
                 error = CKTmkCur(ckt,&tmp,here->VSRCname,"branch");
                 if(error) return(error);