Add a function to access the user data in cases the context is known but not the connection

include/civetweb.h

@@ -251,6 +251,10 @@ CIVETWEB_API const char *mg_get_option(const struct mg_context *ctx, const char
 CIVETWEB_API struct mg_context *mg_get_context(struct mg_connection *conn);
 
 
+/* Get user data passed to mg_start from context. */
+CIVETWEB_API void *mg_get_user_data(struct mg_context *ctx);
+
+
 #if defined(MG_LEGACY_INTERFACE)
 /* Return array of strings that represent valid configuration options.
    For each option, option name and default value is returned, i.e. the

src/civetweb.c

@@ -1065,6 +1065,11 @@ struct mg_context *mg_get_context(struct mg_connection * conn)
     return (conn == NULL) ? (struct mg_context *)NULL : &(conn->ctx);
 }
 
+void *mg_get_user_data(struct mg_context *ctx) 
+{
+    return (ctx == NULL) ? NULL : ctx->user_data;
+}
+
 size_t mg_get_ports(const struct mg_context *ctx, size_t size, int* ports, int* ssl)
 {
     size_t i;