Prevent a crash if hash model table was not generated,

e.g. due to missing valid models.

src/spicelib/parser/inpgmod.c

@@ -343,31 +343,33 @@ INPgetMod(CKTcircuit *ckt, char *name, INPmodel **model, INPtables *tab)
     printf("In INPgetMod, examining model %s ...\n", name);
 #endif
 
-    modtmp = nghash_find(modtabhash, name);
-    if (modtmp) {
-        /* found the model in question - now instantiate if necessary */
-        /* and return an appropriate pointer to it */
+    if (modtabhash) {
+        modtmp = nghash_find(modtabhash, name);
+        if (modtmp) {
+            /* found the model in question - now instantiate if necessary */
+            /* and return an appropriate pointer to it */
 
-/* if illegal device type */
-        if (modtmp->INPmodType < 0) {
+    /* if illegal device type */
+            if (modtmp->INPmodType < 0) {
 #ifdef TRACE
-            printf("In INPgetMod, illegal device type for model %s ...\n", name);
+                printf("In INPgetMod, illegal device type for model %s ...\n", name);
 #endif
-            * model = NULL;
-            return tprintf("Unknown device type for model %s\n", name);
-        }
+                * model = NULL;
+                return tprintf("Unknown device type for model %s\n", name);
+            }
 
-        /* create unless model is already defined */
-        if (!modtmp->INPmodfast) {
-            int error = create_model(ckt, modtmp, tab);
-            if (error) {
-                *model = NULL;
-                return INPerror(error);
+            /* create unless model is already defined */
+            if (!modtmp->INPmodfast) {
+                int error = create_model(ckt, modtmp, tab);
+                if (error) {
+                    *model = NULL;
+                    return INPerror(error);
+                }
             }
-        }
 
-        *model = modtmp;
-        return NULL;
+            *model = modtmp;
+            return NULL;
+        }
     }
 #if (0)
     for (modtmp = modtab; modtmp; modtmp = modtmp->INPnextModel) {