try to fix some binding errors

src/bind_eressea.c

@@ -51,6 +51,7 @@ int eressea_read_orders(const char * filename) {
 }
 
 int eressea_export_json(const char * filename, int flags) {
+    if (filename) {
         FILE *F = fopen(filename, "w");
         if (F) {
             stream out = { 0 };
@@ -61,6 +62,7 @@ int eressea_export_json(const char * filename, int flags) {
             return err;
         }
         perror(filename);
+    }
     return -1;
 }
 

src/bind_ship.c

@@ -124,6 +124,16 @@ static int tolua_ship_set_display(lua_State * L)
 }
 
 static int tolua_ship_get_units(lua_State * L)
+{
+#ifndef TOLUA_RELEASE
+tolua_Error tolua_err;
+if (
+!tolua_isusertype(L,1,"ship",0,&tolua_err) || 
+!tolua_isuserdata(L,2,0,&tolua_err) || 
+!tolua_isnoobj(L,3,&tolua_err)
+) goto tolua_lerror;
+else
+#endif
  {
     ship *sh = (ship *)tolua_tousertype(L, 1, NULL);
     unit **unit_ptr = (unit **)lua_newuserdata(L, sizeof(unit *));
@@ -139,6 +149,12 @@ static int tolua_ship_get_units(lua_State * L)
     lua_pushcclosure(L, tolua_unitlist_nexts, 1);
     return 1;
  }
+#ifndef TOLUA_RELEASE
+ tolua_lerror:
+ tolua_error(L, "#ferror in function 'export'.", &tolua_err);
+ return 0;
+#endif
+}
 
 static int tolua_ship_create(lua_State * L)
 {

src/bind_unit.c

@@ -760,8 +760,9 @@ static int tolua_unit_clear_attribs(lua_State *L) {
 }
 
 static int tolua_unit_has_attrib(lua_State *L) {
-    unit *u = (unit *)tolua_tousertype(L, 1, 0);
+    unit *u = (unit *)tolua_tousertype(L, 1, NULL);
-    const char *name = tolua_tostring(L, 2, 0);
+    const char *name = tolua_tostring(L, 2, NULL);
+    if (u && name) {
         attrib * a = u->attribs;
         while (a) {
             if (strcmp(a->type->name, name) == 0) {
@@ -772,6 +773,8 @@ static int tolua_unit_has_attrib(lua_State *L) {
         lua_pushboolean(L, a != NULL);
         return 1;
     }
+    return 0;
+}
 
 static int tolua_unit_get_key(lua_State * L)
 {

src/bindings.c

@@ -293,7 +293,8 @@ static int tolua_create_curse(lua_State * L)
             ap = &target->attribs;
     }
     if (ap) {
-        const char *cname = tolua_tostring(L, 3, 0);
+        const char *cname = tolua_tostring(L, 3, NULL);
+        if (cname) {
             const curse_type *ctype = ct_find(cname);
             if (ctype) {
                 float vigour = (float)tolua_tonumber(L, 4, 0);
@@ -307,6 +308,7 @@ static int tolua_create_curse(lua_State * L)
                 }
             }
         }
+    }
     tolua_pushboolean(L, false);
     return 1;
 }