From c497557286e5005de07d918626abcea85fd6be3b Mon Sep 17 00:00:00 2001
From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Sat, 7 Aug 2021 19:07:48 +0100
Subject: [PATCH] config: Do not use Default for constructing Aggregate

We are going to want to add a non-Default field, in a bit.

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
---
 src/config.rs | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/src/config.rs b/src/config.rs
index 4e9c710..f08fe71 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -161,7 +161,7 @@ pub struct Config {
 static OUTSIDE_SECTION: &str = "[";
 static SPECIAL_SERVER_SECTION: &str = "SERVER";
 
-#[derive(Default,Debug)]
+#[derive(Debug)]
 struct Aggregate {
   keys_allowed: HashMap<&'static str, SectionKindList>,
   sections: HashMap<SectionName, SectionMap>,
@@ -221,6 +221,13 @@ impl Display for SectionName {
 }
 
 impl Aggregate {
+  fn new(
+    keys_allowed: HashMap<&'static str, SectionKindList>
+  ) -> Self { Aggregate {
+    keys_allowed,
+    sections: default(),
+  } }
+
   #[throws(AE)] // AE does not include path
   fn read_file<A>(&mut self, path: &Path, anyway: OkAnyway<A>) -> Option<A>
   {
@@ -804,9 +811,8 @@ impl InstanceConfig {
 #[throws(AE)]
 pub fn read(opts: &Opts, end: LinkEnd) -> Vec<InstanceConfig> {
   let agg = (||{
-    let mut agg = Aggregate::default();
-    agg.keys_allowed.extend(
-      InstanceConfig::FIELDS.iter().cloned()
+    let mut agg = Aggregate::new(
+      InstanceConfig::FIELDS.iter().cloned().collect(),
     );
 
     agg.read_string(DEFAULT_CONFIG.into(),
-- 
2.30.2