🚑 Fix segmentation fault is supplying an unknown long argument

src/main.c

@@ -116,6 +116,8 @@ int main(int argc, char *argv[]) {
     //Optionally perform xdelta3
     if (state.prevFile) {
       //TODO
+      fprintf(stderr, "xdelta3 is not yet implemented.\n");
+      errorAndExit();
     }
   }
 

src/parseArguments.c

@@ -15,6 +15,7 @@ static struct option long_options[] = {
   {"size", required_argument, 0, 's'},
   {"keys", required_argument, 0, 'k'},
   {"prev", required_argument, 0, 'p'},
+  {NULL, 0, 0, 0},
 };
 
 
@@ -74,7 +75,7 @@ struct arguments parseArguments(int argc, char *argv[]) {
         break;
       }
       case 'p': //prev file for xdelta3
-        //TODO
+        state.prevFile = optarg;
         break;
       case '?':
         errorAndExit();
@@ -101,7 +102,7 @@ struct arguments parseArguments(int argc, char *argv[]) {
   }
 
   if (optind < argc) {
-    fprintf(stderr, "Found %i arguments without an option. All arguments must be preceded by an option.\n", argc - optind);
+    fprintf(stderr, "Found %i argument(s) without an option. All arguments must be preceded by an option.\n", argc - optind);
     errorAndExit();
   }