src: fix uv_err_name memory leak

Author: theanarkh

src/util.h

@@ -922,7 +922,6 @@ void SetConstructorFunction(v8::Local<v8::Context> context,
                             v8::Local<v8::FunctionTemplate> tmpl,
                             SetConstructorFunctionFlag flag =
                                 SetConstructorFunctionFlag::SET_CLASS_NAME);
-
 }  // namespace node
 
 #endif  // defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS

src/uv.cc

@@ -73,7 +73,8 @@ void ErrName(const FunctionCallbackInfo<Value>& args) {
   int err;
   if (!args[0]->Int32Value(env->context()).To(&err)) return;
   CHECK_LT(err, 0);
-  const char* name = uv_err_name(err);
+  char name[50];
+  uv_err_name_r(err, name, sizeof(name));
   args.GetReturnValue().Set(OneByteString(env->isolate(), name));
 }
 

test/parallel/test-uv-errno.js

@@ -12,6 +12,8 @@ const { internalBinding } = require('internal/test/binding');
 const uv = internalBinding('uv');
 const keys = Object.keys(uv);
 
+assert.strictEqual(uv.errname(-111111), 'Unknown system error -111111');
+
 keys.forEach((key) => {
   if (!key.startsWith('UV_'))
     return;