From 83edde639fe2e1fc40ff4694ee0af5481b8e25a1 Mon Sep 17 00:00:00 2001
From: Jason Volk <jason@zemos.net>
Date: Thu, 30 Aug 2018 10:58:32 -0700
Subject: [PATCH] ircd::http: Improve query::string::at() error message to show
 key name.

---
 ircd/http.cc | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/ircd/http.cc b/ircd/http.cc
index 6045ae715..19a0c7899 100644
--- a/ircd/http.cc
+++ b/ircd/http.cc
@@ -523,7 +523,18 @@ const
 {
 	const auto ret(operator[](key));
 	if(ret.empty())
-		throw std::out_of_range{"Failed to find value for required query string key"};
+	{
+		thread_local char buf[1024];
+		const string_view msg{fmt::sprintf
+		{
+			buf, "Failed to find value for required query string key '%s'", key
+		}};
+
+		throw std::out_of_range
+		{
+			msg.c_str() // fmt::sprintf() will null terminate msg
+		};
+	}
 
 	return ret;
 }