Custom config locations should be used in bootstrap environment too

inject/custom-config/bootstrap.yml

@@ -0,0 +1,17 @@
+#
+# Copyright 2017-2025 original authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+custom-bootstrap-value: test

inject/src/main/java/io/micronaut/context/DefaultApplicationContext.java

@@ -832,6 +832,12 @@ public Optional<MutableConversionService> getConversionService() {
                 public ClassPathResourceLoader getResourceLoader() {
                     return resourceLoader;
                 }
+
+                @Nullable
+                @Override
+                public List<String> getOverrideConfigLocations() {
+                    return configuration.getOverrideConfigLocations();
+                }
             });
         }
 

inject/src/main/java/io/micronaut/context/env/DefaultEnvironment.java

@@ -169,8 +169,9 @@ public DefaultEnvironment(@NonNull ApplicationContextConfiguration configuration
         if (!environments.isEmpty()) {
             log.info("Established active environments: {}", environments);
         }
-        List<String> configLocations = configuration.getOverrideConfigLocations() == null ?
-                new ArrayList<>(DEFAULT_CONFIG_LOCATIONS) : configuration.getOverrideConfigLocations();
+        List<String> configLocations = configuration.getOverrideConfigLocations() == null
+            ? new ArrayList<>(DEFAULT_CONFIG_LOCATIONS)
+            : new ArrayList<>(configuration.getOverrideConfigLocations());
         // Search config locations in reverse order
         Collections.reverse(configLocations);
         this.configLocations = configLocations;

inject/src/test/groovy/io/micronaut/context/env/DefaultEnvironmentSpec.groovy

@@ -67,6 +67,7 @@ class DefaultEnvironmentSpec extends Specification {
         env.getProperty("test.foo", Map.class).get() == [bar: "10", baz: "20"]
     }
 
+    @RestoreSystemProperties
     void "test environment refresh and diff"() {
         given:
         System.setProperty(Environment.BOOTSTRAP_CONTEXT_PROPERTY, StringUtils.TRUE)
@@ -515,6 +516,24 @@ class DefaultEnvironmentSpec extends Specification {
             applicationContext.stop()
     }
 
+    @RestoreSystemProperties
+    void "test custom config locations used in bootstrap environment"() {
+        given:
+        System.setProperty(Environment.BOOTSTRAP_CONTEXT_PROPERTY, StringUtils.TRUE)
+
+        when:
+        ApplicationContext applicationContext = ApplicationContext.builder()
+                .overrideConfigLocations("file:./custom-config/")
+                .build()
+                .start()
+
+        then:
+        applicationContext.getRequiredProperty("custom-bootstrap-value", String.class) == "test"
+
+        cleanup:
+        applicationContext.stop()
+    }
+
     void "test custom config locations respect environment order"() {
         when:
             ApplicationContext applicationContext = ApplicationContext.builder()