From 8fcbdadfad8a9b3143527141ff37e5fe1e87f3b3 Mon Sep 17 00:00:00 2001
From: willcl-ark <will@256k1.dev>
Date: Thu, 9 Mar 2023 22:25:01 +0000
Subject: [PATCH] util: fix argsman dupe key error

fixes #22638

If we find a duplicate key and error, clear `values` before returning so that
WriteSettings will write an empty file, therefore clearing it.

This aligns with GUI behaviour added in 1ee6d0b.
---
 src/test/settings_tests.cpp | 3 ++-
 src/util/settings.cpp       | 2 ++
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/test/settings_tests.cpp b/src/test/settings_tests.cpp
index 0feb68b9b1..ad12c46561 100644
--- a/src/test/settings_tests.cpp
+++ b/src/test/settings_tests.cpp
@@ -80,7 +80,7 @@ BOOST_AUTO_TEST_CASE(ReadWrite)
     BOOST_CHECK(values.empty());
     BOOST_CHECK(errors.empty());
 
-    // Check duplicate keys not allowed
+    // Check duplicate keys not allowed and that values returns empty if a duplicate is found.
     WriteText(path, R"({
         "dupe": "string",
         "dupe": "dupe"
@@ -88,6 +88,7 @@ BOOST_AUTO_TEST_CASE(ReadWrite)
     BOOST_CHECK(!util::ReadSettings(path, values, errors));
     std::vector<std::string> dup_keys = {strprintf("Found duplicate key dupe in settings file %s", fs::PathToString(path))};
     BOOST_CHECK_EQUAL_COLLECTIONS(errors.begin(), errors.end(), dup_keys.begin(), dup_keys.end());
+    BOOST_CHECK(values.empty());
 
     // Check non-kv json files not allowed
     WriteText(path, R"("non-kv")");
diff --git a/src/util/settings.cpp b/src/util/settings.cpp
index 2b25b7f0e1..a2e30098dc 100644
--- a/src/util/settings.cpp
+++ b/src/util/settings.cpp
@@ -99,6 +99,8 @@ bool ReadSettings(const fs::path& path, std::map<std::string, SettingsValue>& va
         auto inserted = values.emplace(in_keys[i], in_values[i]);
         if (!inserted.second) {
             errors.emplace_back(strprintf("Found duplicate key %s in settings file %s", in_keys[i], fs::PathToString(path)));
+            values.clear();
+            break;
         }
     }
     return errors.empty();