Fix log_prefix initialization. (proxy-wasm#124)

Signed-off-by: mathetake <[email protected]>

Author: mathetake

include/proxy-wasm/context.h

@@ -50,7 +50,8 @@ struct PluginBase {
              std::string_view runtime, std::string_view plugin_configuration, bool fail_open)
       : name_(std::string(name)), root_id_(std::string(root_id)), vm_id_(std::string(vm_id)),
         runtime_(std::string(runtime)), plugin_configuration_(plugin_configuration),
-        fail_open_(fail_open), key_(root_id_ + "||" + plugin_configuration_) {}
+        fail_open_(fail_open), key_(root_id_ + "||" + plugin_configuration_),
+        log_prefix_(makeLogPrefix()) {}
 
   const std::string name_;
   const std::string root_id_;

src/context.cc

@@ -96,7 +96,7 @@ std::string PluginBase::makeLogPrefix() const {
   if (!root_id_.empty()) {
     prefix = prefix + " " + std::string(root_id_);
   }
-  if (vm_id_.empty()) {
+  if (!vm_id_.empty()) {
     prefix = prefix + " " + std::string(vm_id_);
   }
   return prefix;
@@ -134,7 +134,7 @@ std::string ContextBase::makeRootLogPrefix(std::string_view vm_id) const {
   if (!root_id_.empty()) {
     prefix = prefix + " " + std::string(root_id_);
   }
-  if (vm_id.empty()) {
+  if (!vm_id.empty()) {
     prefix = prefix + " " + std::string(vm_id);
   }
   return prefix;