Restore per-request credential override in AwsExecutionContextBuilder

core/aws-core/src/main/java/software/amazon/awssdk/awscore/internal/AwsExecutionContextBuilder.java

@@ -31,6 +31,7 @@
 import software.amazon.awssdk.auth.credentials.AwsCredentials;
 import software.amazon.awssdk.auth.signer.AwsSignerExecutionAttribute;
 import software.amazon.awssdk.awscore.AwsExecutionAttribute;
+import software.amazon.awssdk.awscore.AwsRequestOverrideConfiguration;
 import software.amazon.awssdk.awscore.client.config.AwsClientOption;
 import software.amazon.awssdk.awscore.internal.authcontext.AuthorizationStrategy;
 import software.amazon.awssdk.awscore.internal.authcontext.AuthorizationStrategyFactory;
@@ -307,14 +308,36 @@ private static void putAuthSchemeResolutionAttributes(ExecutionAttributes execut
         //  request preferred over client.
         Map<String, AuthScheme<?>> authSchemes = clientConfig.option(SdkClientOption.AUTH_SCHEMES);
 
-        IdentityProviders identityProviders = clientConfig.option(SdkClientOption.IDENTITY_PROVIDERS);
+        IdentityProviders identityProviders = resolveIdentityProviders(originalRequest, clientConfig);
 
         executionAttributes
             .putAttribute(SdkInternalExecutionAttribute.AUTH_SCHEME_RESOLVER, authSchemeProvider)
             .putAttribute(SdkInternalExecutionAttribute.AUTH_SCHEMES, authSchemes)
             .putAttribute(SdkInternalExecutionAttribute.IDENTITY_PROVIDERS, identityProviders);
     }
 
+    private static IdentityProviders resolveIdentityProviders(SdkRequest originalRequest,
+                                                              SdkClientConfiguration clientConfig) {
+        IdentityProviders identityProviders = clientConfig.option(SdkClientOption.IDENTITY_PROVIDERS);
+
+        // identityProviders can be null, for new core with old client. In this case, even if AwsRequestOverrideConfiguration
+        // has credentialsIdentityProvider set (because it is in new core), it is ok to not setup IDENTITY_PROVIDERS, as old
+        // client won't have AUTH_SCHEME_PROVIDER/AUTH_SCHEMES set either, which are also needed for SRA logic.
+        if (identityProviders == null) {
+            return null;
+        }
+
+        return originalRequest
+            .overrideConfiguration()
+            .filter(c -> c instanceof AwsRequestOverrideConfiguration)
+            .map(c -> (AwsRequestOverrideConfiguration) c)
+            .map(c -> identityProviders.copy(b -> {
+                c.credentialsIdentityProvider().ifPresent(b::putIdentityProvider);
+                c.tokenIdentityProvider().ifPresent(b::putIdentityProvider);
+            }))
+            .orElse(identityProviders);
+    }
+
     /**
      * Finalize {@link SdkRequest} by running beforeExecution and modifyRequest interceptors.
      *

core/aws-core/src/test/java/software/amazon/awssdk/awscore/internal/AwsExecutionContextBuilderTest.java

@@ -581,6 +581,45 @@ public void invokeInterceptorsAndCreateExecutionContext_noAuthSchemeProviderRequ
         assertThat(actualProvider).isSameAs(clientAuthSchemeProvider);
     }
 
+    /**
+     * Per-request credential override via AwsRequestOverrideConfiguration.credentialsProvider() must be
+     * reflected in IDENTITY_PROVIDERS even when AUTH_SCHEME_OPTIONS_RESOLVER is not set (old service client).
+     */
+    @Test
+    public void postSra_requestCredentialOverride_withoutAuthSchemeOptionsResolver_identityProvidersHasOverride() {
+        IdentityProvider<AwsCredentialsIdentity> requestCredsProvider =
+            StaticCredentialsProvider.create(AwsBasicCredentials.create("request-akid", "request-skid"));
+
+        SdkRequest request = NoopTestAwsRequest.builder()
+            .overrideConfiguration(AwsRequestOverrideConfiguration.builder()
+                                                                   .credentialsProvider(requestCredsProvider)
+                                                                   .build())
+            .build();
+
+        IdentityProviders clientIdentityProviders = IdentityProviders.builder()
+            .putIdentityProvider(defaultCredentialsProvider)
+            .build();
+
+        SdkClientConfiguration clientConfig = testClientConfiguration()
+            .option(SdkClientOption.IDENTITY_PROVIDERS, clientIdentityProviders)
+            .option(SdkClientOption.EXECUTION_INTERCEPTORS, Collections.emptyList())
+            .build();
+
+        // No AUTH_SCHEME_OPTIONS_RESOLVER set — simulates old service client
+        ClientExecutionParams<SdkRequest, SdkResponse> executionParams = clientExecutionParams(request);
+
+        ExecutionContext executionContext =
+            AwsExecutionContextBuilder.invokeInterceptorsAndCreateExecutionContext(executionParams, clientConfig);
+
+        IdentityProviders resolvedProviders =
+            executionContext.executionAttributes().getAttribute(SdkInternalExecutionAttribute.IDENTITY_PROVIDERS);
+
+        // The per-request credential override must be reflected in IDENTITY_PROVIDERS
+        IdentityProvider<AwsCredentialsIdentity> resolvedCredProvider =
+            resolvedProviders.identityProvider(AwsCredentialsIdentity.class);
+        assertThat(resolvedCredProvider).isSameAs(requestCredsProvider);
+    }
+
     private ClientExecutionParams<SdkRequest, SdkResponse> clientExecutionParams() {
         return clientExecutionParams(sdkRequest);
     }