Test: Allow merging mock secure settings (#25387)

While real secure settings (ie an ES keystore) cannot be merged
together, mocked secure settings can and need to be sometimes merged.
This commit adds a merge method to allow tests to merge together
multiple instances of secure settings.

2 files changed, 6 insertions, 2 deletions

diff --git a/core/src/main/java/org/elasticsearch/common/settings/Settings.java b/core/src/main/java/org/elasticsearch/common/settings/Settings.java
index e444dea6b7..182ea6ccb1 100644
--- a/core/src/main/java/org/elasticsearch/common/settings/Settings.java
+++ b/core/src/main/java/org/elasticsearch/common/settings/Settings.java
@@ -718,6 +718,10 @@ public final class Settings implements ToXContent {
             if (secureSettings.isLoaded() == false) {
                 throw new IllegalStateException("Secure settings must already be loaded");
             }
+            if (this.secureSettings.get() != null) {
+                throw new IllegalArgumentException("Secure settings already set. Existing settings: " +
+                    this.secureSettings.get().getSettingNames() + ", new settings: " + secureSettings.getSettingNames());
+            }
             this.secureSettings.set(secureSettings);
             return this;
         }
diff --git a/core/src/main/java/org/elasticsearch/transport/TcpTransport.java b/core/src/main/java/org/elasticsearch/transport/TcpTransport.java
index 5db64c98b8..9631fc977c 100644
--- a/core/src/main/java/org/elasticsearch/transport/TcpTransport.java
+++ b/core/src/main/java/org/elasticsearch/transport/TcpTransport.java
@@ -677,8 +677,8 @@ public abstract class TcpTransport<Channel> extends AbstractLifecycleComponent i
                 continue;
             }
             Settings mergedSettings = Settings.builder()
-                .put(defaultSettings)
-                .put(profileSettings)
+                .put(defaultSettings.getAsMap())
+                .put(profileSettings.getAsMap())
                 .build();
             result.put(name, mergedSettings);
         }