Don't silently accept wrong user input (missing nodes, values).

Check for at leat 4 tokens (name, n1, n2, val/model/...).
If the instance has not been set up correctly, bail out, prevent crash.

src/spicelib/parser/inp2c.c

@@ -32,7 +32,7 @@ void INP2C(CKTcircuit *ckt, INPtables * tab, struct card *current)
     int error1;          /* secondary error code temporary */
     INPmodel *thismodel; /* pointer to model structure describing our model */
     GENmodel *mdfast = NULL; /* pointer to the actual model */
-    GENinstance *fast;   /* pointer to the actual instance */
+    GENinstance *fast = NULL;/* pointer to the actual instance */
     IFvalue ptemp;       /* a value structure to package resistance into */
     int waslead;         /* flag to indicate that funny unlabeled number was found */
     double leadval;      /* actual value of unlabeled number */
@@ -49,11 +49,25 @@ void INP2C(CKTcircuit *ckt, INPtables * tab, struct card *current)
         }
     }
     line = current->line;
-    INPgetNetTok(&line, &name, 1);
+
+    INPgetNetTok(&line, &name, 1);			/* Cname */
+    if (*line == '\0') {
+        fprintf(stderr, "\nWarning: '%s' is not a valid capacitor instance line, ignored!\n\n", current->line);
+        return;
+    }
+    INPgetNetTok(&line, &nname1, 1);		/* <node> */
+    if (*line == '\0') {
+        fprintf(stderr, "\nWarning: '%s' is not a valid capacitor instance line, ignored!\n\n", current->line);
+        return;
+    }
+    INPgetNetTok(&line, &nname2, 1);		/* <node> */
+    if (*line == '\0') {
+        fprintf(stderr, "\nWarning: '%s' is not a valid capacitor instance line, ignored!\n\n", current->line);
+        return;
+    }
+
     INPinsert(&name, tab);
-    INPgetNetTok(&line, &nname1, 1);
     INPtermInsert(ckt, &nname1, tab, &node1);
-    INPgetNetTok(&line, &nname2, 1);
     INPtermInsert(ckt, &nname2, tab, &node2);
 
     /* enable reading values like 4u7 */
@@ -109,7 +123,12 @@ void INP2C(CKTcircuit *ckt, INPtables * tab, struct card *current)
 #endif
       }
     }
-    
+
+    if (!fast || !fast->GENmodPtr) {
+        fprintf(stderr, "\nWarning: Instance for capacitor '%s' could not be set up properly, ignored!\n\n", current->line);
+        return;
+    }
+
     if (error1 == 0) {        /* Looks like a number */
       ptemp.rValue = val;
       GCA(INPpName, ("capacitance", &ptemp, ckt, type, fast));

src/spicelib/parser/inp2l.c

@@ -32,7 +32,7 @@ void INP2L(CKTcircuit *ckt, INPtables * tab, struct card *current)
     int error1;          /* secondary error code temporary */
     INPmodel *thismodel; /* pointer to model structure describing our model */
     GENmodel *mdfast = NULL; /* pointer to the actual model */
-    GENinstance *fast;          /* pointer to the actual instance */
+    GENinstance *fast = NULL;/* pointer to the actual instance */
     IFvalue ptemp;       /* a value structure to package inductance into */
     int waslead;         /* flag to indicate that funny unlabeled number was found */
     double leadval;      /* actual value of unlabeled number */
@@ -49,15 +49,26 @@ void INP2L(CKTcircuit *ckt, INPtables * tab, struct card *current)
         }
     }
     line = current->line;
-    INPgetNetTok(&line, &name, 1);
+    INPgetNetTok(&line, &name, 1);			/* Lname */
+    if (*line == '\0') {
+        fprintf(stderr, "\nWarning: '%s' is not a valid inductor instance line, ignored!\n\n", current->line);
+        return;
+    }
+    INPgetNetTok(&line, &nname1, 1);		/* <node> */
+    if (*line == '\0') {
+        fprintf(stderr, "\nWarning: '%s' is not a valid inductor instance line, ignored!\n\n", current->line);
+        return;
+    }
+    INPgetNetTok(&line, &nname2, 1);		/* <node> */
+    if (*line == '\0') {
+        fprintf(stderr, "\nWarning: '%s' is not a valid inductor instance line, ignored!\n\n", current->line);
+        return;
+    }
+
     INPinsert(&name, tab);
-    INPgetNetTok(&line, &nname1, 1);
     INPtermInsert(ckt, &nname1, tab, &node1);
-    INPgetNetTok(&line, &nname2, 1);
     INPtermInsert(ckt, &nname2, tab, &node2);
 
-//    val = INPevaluate(&line, &error1, 1);
-
     /* enable reading values like 4u7 */
     if (newcompat.lt)
         val = INPevaluateRKM_L(&line, &error1, 1);	/* [<val>] */
@@ -110,7 +121,12 @@ void INP2L(CKTcircuit *ckt, INPtables * tab, struct card *current)
 #endif
       }
     }
-    
+
+    if (!fast || !fast->GENmodPtr) {
+        fprintf(stderr, "\nWarning: Instance for inductor '%s' could not be set up properly, ignored!\n\n", current->line);
+        return;
+    }
+
     if (error1 == 0) {        /* Looks like a number */
       ptemp.rValue = val;
       GCA(INPpName, ("inductance", &ptemp, ckt, type, fast));

src/spicelib/parser/inp2r.c

@@ -39,7 +39,7 @@ void INP2R(CKTcircuit *ckt, INPtables * tab, struct card *current)
     int error1;			/* secondary error code temporary */
     INPmodel *thismodel;	/* pointer to model structure describing our model */
     GENmodel *mdfast = NULL;	/* pointer to the actual model */
-    GENinstance *fast;		/* pointer to the actual instance */
+    GENinstance *fast = NULL;		/* pointer to the actual instance */
     IFvalue ptemp;		/* a value structure to package resistance into */
     int waslead;		/* flag to indicate that funny unlabeled number was found */
     double leadval;		/* actual value of unlabeled number */
@@ -59,10 +59,23 @@ void INP2R(CKTcircuit *ckt, INPtables * tab, struct card *current)
     }
     line = current->line;
     INPgetNetTok(&line, &name, 1);			/* Rname */
-    INPinsert(&name, tab);
+    if (*line == '\0') {
+        fprintf(stderr, "\nWarning: '%s' is not a valid resistor instance line, ignored!\n\n", current->line);
+        return;
+    }
     INPgetNetTok(&line, &nname1, 1);		/* <node> */
-    INPtermInsert(ckt, &nname1, tab, &node1);
+    if (*line == '\0') {
+        fprintf(stderr, "\nWarning: '%s' is not a valid resistor instance line, ignored!\n\n", current->line);
+        return;
+    }
     INPgetNetTok(&line, &nname2, 1);		/* <node> */
+    if (*line == '\0') {
+        fprintf(stderr, "\nWarning: '%s' is not a valid resistor instance line, ignored!\n\n", current->line);
+        return;
+    }
+
+    INPinsert(&name, tab);
+    INPtermInsert(ckt, &nname1, tab, &node1);
     INPtermInsert(ckt, &nname2, tab, &node2);
 
     /* enable reading values like 4k7 */
@@ -197,6 +210,11 @@ void INP2R(CKTcircuit *ckt, INPtables * tab, struct card *current)
       }
     }
 
+    if (!fast || !fast->GENmodPtr) {
+        fprintf(stderr, "\nWarning: Instance for resistor '%s' could not be set up properly, ignored!\n\n", current->line);
+        return;
+    }
+
     if (error1 == 0) {		/* got a resistance above */
       ptemp.rValue = val;
       GCA(INPpName, ("resistance", &ptemp, ckt, type, fast));