fix bugs in passing env variables

src/mcp_stdio_client.cpp

@@ -205,6 +205,19 @@ bool stdio_client::start_server_process() {
     
     LOG_INFO("Starting server process: ", command_);
 
+    auto convert_to_string = [](const json& value) -> std::string {
+        if (value.is_string()) {
+            return value.get<std::string>();
+        } else if (value.is_number_integer()) {
+            return std::to_string(value.get<int>());
+        } else if (value.is_number_float()) {
+            return std::to_string(value.get<double>());
+        } else if (value.is_boolean()) {
+            return value.get<bool>() ? "true" : "false";
+        }
+        throw std::runtime_error("Unsupported type");
+    };
+    
 #if defined(_WIN32) || defined(_WIN64)
     // Windows实现
     SECURITY_ATTRIBUTES sa;
@@ -262,26 +275,11 @@ bool stdio_client::start_server_process() {
     // 准备环境变量
     std::string env_block;
     if (!env_vars_.empty()) {
-        char* system_env = GetEnvironmentStringsA();
+        for (const auto& [key, value] : env_vars_.items()) {
-        if (system_env) {
+            std::string env_var = key + "=" + convert_to_string(value);
-            // 复制系统环境变量
+            env_block += env_var + '\0';
-            const char* env_ptr = system_env;
-            while (*env_ptr) {
-                std::string env_var(env_ptr);
-                env_block += env_var + '\0';
-                env_ptr += env_var.size() + 1;
-            }
-            FreeEnvironmentStringsA(system_env);
-            
-            // 添加自定义环境变量
-            for (auto it = env_vars_.begin(); it != env_vars_.end(); ++it) {
-                std::string env_var = it.key() + "=" + it.value().get<std::string>();
-                env_block += env_var + '\0';
-            }
-            
-            // 添加结束符
-            env_block += '\0';
         }
+        env_block += '\0';
     }
     
     // 创建子进程
@@ -359,10 +357,10 @@ bool stdio_client::start_server_process() {
         
         // 设置环境变量
         if (!env_vars_.empty()) {
-            for (auto it = env_vars_.begin(); it != env_vars_.end(); ++it) {
+            for (const auto& [key, value] : env_vars_.items()) {
-                std::string env_var = it.key() + "=" + it.value().get<std::string>();
+                std::string env_var = key + "=" + convert_to_string(value);
                 if (putenv(const_cast<char*>(env_var.c_str())) != 0) {
-                    LOG_ERROR("Failed to set environment variable: ", it.key());
+                    LOG_ERROR("Failed to set environment variable: ", key);
                 }
             }
         }