Avoid __p_error on Windows

Signed-off-by: Michael Carroll <[email protected]>

src/Environment.cc

@@ -127,28 +127,55 @@ bool clearenv()
 /////////////////////////////////////////////////
 EnvironmentMap env()
 {
-  // Portable method for reading environment variables
-  // Ref: https://stackoverflow.com/a/71483564/460065
-  char **currentEnv {nullptr};
-#if defined(WIN) && (_MSC_VER >= 1900)
-  currentEnv =  *__p_environ();
-#else
-  currentEnv = environ;
-#endif
+  EnvironmentMap ret;
+#ifdef _WIN32
+  DWORD environment_block_size = GetEnvironmentBlockSize();
+
+  // Allocate a buffer to store the environment block.
+  LPCH env_buf = (LPCH)malloc(environment_block_size);
+  if (env_buf == nullptr) {
+    return {};
+  }
+  // Get the environment block.
+  if (!GetEnvironmentVariables(env_buf, environment_block_size)) {
+    free(env_buf);
+    return {};
+  }
+  // Parse the environment block into an unordered_map.
+  LPCH env_var = env_buf;
+  while (*env_var != '\0') {
+    // Split the environment variable into a key-value pair.
+    char* equal_sign = strchr(env_var, '=');
+    if (equal_sign == nullptr) {
+      continue;
+    }
+
+    // Get the key and value of the environment variable.
+    std::string key(env_var, equal_sign - env_var);
+    std::string value(equal_sign + 1);
+
+    // Add the key-value pair to the unordered_map.
+    ret[key] = value;
 
+    // Advance to the next environment variable.
+    env_var = equal_sign + 1;
+  }
+  free(env_buf);
+#else
+  char **currentEnv = environ;
   // In the case that clearenv() was just called
   // currentEnv will be nullptr
   if (currentEnv == nullptr)
     return {};
 
-  EnvironmentMap ret;
   for (; *currentEnv; ++currentEnv)
   {
     std::string var(*currentEnv);
     auto key = var.substr(0, var.find('='));
     var.erase(0, var.find('=') + 1);
     ret[key] = var;
   }
+#endif
   return ret;
 }