windows.c: Return nil,err from functions instead of throwing errors.

diff --git a/util-src/windows.c b/util-src/windows.c
index e1e07608756ae1f9be01d019555fa4ef5d458f78..121cc47153ba465ce25feeccde25a315e5c4f789 100644 (file)
--- a/util-src/windows.c
+++ b/util-src/windows.c
@@ -38,15 +38,16 @@ static int Lget_nameservers(lua_State *L) {
                }
                return 1;
        } else {
-               luaL_error(L, "DnsQueryConfig returned %d", status);
-               return 0; // unreachable, but prevents a compiler warning
+               lua_pushnil(L);
+               lua_pushfstring(L, "DnsQueryConfig returned %d", status);
+               return 2;
        }
 }
 
-static void lassert(lua_State *L, BOOL test, char* string) {
-       if (!test) {
-               luaL_error(L, "%s: %d", string, GetLastError());
-       }
+static int lerror(lua_State *L, char* string) {
+       lua_pushnil(L);
+       lua_pushfstring(L, "%s: %d", string, GetLastError());
+       return 2;
 }
 
 static int Lget_consolecolor(lua_State *L) {
@@ -55,9 +56,9 @@ static int Lget_consolecolor(lua_State *L) {
        
        CONSOLE_SCREEN_BUFFER_INFO info;
        
-       lassert(L, console != INVALID_HANDLE_VALUE, "GetStdHandle");
-       lassert(L, GetConsoleScreenBufferInfo(console, &info), "GetConsoleScreenBufferInfo");
-       lassert(L, ReadConsoleOutputAttribute(console, &color, sizeof(WORD), info.dwCursorPosition, &read_len), "ReadConsoleOutputAttribute");
+       if (console == INVALID_HANDLE_VALUE) return lerror(L, "GetStdHandle");
+       if (!GetConsoleScreenBufferInfo(console, &info)) return lerror(L, "GetConsoleScreenBufferInfo");
+       if (!ReadConsoleOutputAttribute(console, &color, sizeof(WORD), info.dwCursorPosition, &read_len)) return lerror(L, "ReadConsoleOutputAttribute");
 
        lua_pushnumber(L, color);
        return 1;
@@ -65,9 +66,10 @@ static int Lget_consolecolor(lua_State *L) {
 static int Lset_consolecolor(lua_State *L) {
        int color = luaL_checkint(L, 1);
        HWND console = GetStdHandle(STD_OUTPUT_HANDLE);
-       lassert(L, console != INVALID_HANDLE_VALUE, "GetStdHandle");
-       lassert(L, SetConsoleTextAttribute(console, color), "SetConsoleTextAttribute");
-       return 0;
+       if (console == INVALID_HANDLE_VALUE) return lerror(L, "GetStdHandle");
+       if (!SetConsoleTextAttribute(console, color)) return lerror(L, "SetConsoleTextAttribute");
+       lua_pushboolean(L, 1);
+       return 1;
 }
 
 static const luaL_Reg Reg[] =