From 1211a5f9a15ec78ff4d0925aa2d1f7e7824a125a Mon Sep 17 00:00:00 2001
From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Sat, 5 Sep 2020 19:16:10 +0100
Subject: [PATCH] Allow absence of [modules] in TOML file.

Making the modules field of LogSpecification an Option allows it to be
omitted entirely.  This makes an empty log spec TOML valid.

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
---
 src/log_specification.rs | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/src/log_specification.rs b/src/log_specification.rs
index 477e436..3ac2606 100644
--- a/src/log_specification.rs
+++ b/src/log_specification.rs
@@ -252,7 +252,7 @@ impl LogSpecification {
         struct LogSpecFileFormat {
             pub global_level: Option<String>,
             pub global_pattern: Option<String>,
-            pub modules: std::collections::BTreeMap<String, String>,
+            pub modules: Option<std::collections::BTreeMap<String, String>>,
         }
 
         let logspec_ff: LogSpecFileFormat = toml::from_str(s)?;
@@ -266,7 +266,7 @@ impl LogSpecification {
             });
         }
 
-        for (k, v) in logspec_ff.modules {
+        for (k, v) in logspec_ff.modules.unwrap_or_default() {
             module_filters.push(ModuleFilter {
                 module_name: Some(k),
                 level_filter: parse_level_filter(v)?,
@@ -872,6 +872,11 @@ mod test_with_specfile {
 
     #[test]
     fn specfile() {
+        compare_specs(
+            "",
+            "",
+        );
+
         compare_specs(
             "[modules]\n\
              ",