SOLR-10137: Ensure that ConfigSets created via API are mutable.

solr/CHANGES.txt

@@ -252,6 +252,8 @@ Bug Fixes
 
 * SOLR-10360: Solr HDFS snapshot export fails due to FileNotFoundException error when using MR1 instead of
   yarn. (Hrishikesh via Mark Miller)
+  
+* SOLR-10137: Ensure that ConfigSets created via API are mutable. (Hrishikesh via Mark Miller)
 
 Optimizations
 ----------------------

solr/core/src/java/org/apache/solr/handler/admin/ConfigSetsHandler.java

@@ -238,6 +238,10 @@ public class ConfigSetsHandler extends RequestHandlerBase implements PermissionN
         props.put(param, params.get(param));
       }
     }
+
+    // The configset created via an API should be mutable.
+    props.put("immutable", "false");
+
     return props;
   }
 

solr/core/src/test/org/apache/solr/handler/admin/TestConfigsApi.java

@@ -54,6 +54,6 @@ public class TestConfigsApi extends SolrTestCaseJ4 {
         "{name :sample, operation:delete}");
 
     compareOutput(apiBag, "/cluster/configs", POST, "{create:{name : newconf, baseConfigSet: sample }}", null,
-        "{operation:create, name :newconf,  baseConfigSet: sample }");
+        "{operation:create, name :newconf,  baseConfigSet: sample, immutable: false }");
   }
 }