From 0c0056884a6c98ae54920e8b7901c1148609fe66 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Martin=20Barto=C5=A1?= <mabartos@redhat.com>
Date: Tue, 14 Mar 2023 17:30:29 +0100
Subject: [PATCH] NPE when obtaining ConfigValue via getValue

Fixes #906
---
 .../ExpressionConfigSourceInterceptor.java    |  2 +-
 ...ExpressionConfigSourceInterceptorTest.java | 31 +++++++++++++++++++
 2 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/implementation/src/main/java/io/smallrye/config/ExpressionConfigSourceInterceptor.java b/implementation/src/main/java/io/smallrye/config/ExpressionConfigSourceInterceptor.java
index 740799f9f..09b73ecef 100644
--- a/implementation/src/main/java/io/smallrye/config/ExpressionConfigSourceInterceptor.java
+++ b/implementation/src/main/java/io/smallrye/config/ExpressionConfigSourceInterceptor.java
@@ -49,7 +49,7 @@ private ConfigValue getValue(final ConfigSourceInterceptorContext context, final
             return configValue;
         }
 
-        if (configValue == null) {
+        if (configValue == null || configValue.getValue() == null) {
             return null;
         }
 
diff --git a/implementation/src/test/java/io/smallrye/config/ExpressionConfigSourceInterceptorTest.java b/implementation/src/test/java/io/smallrye/config/ExpressionConfigSourceInterceptorTest.java
index 7abe50a76..6ca5abf49 100644
--- a/implementation/src/test/java/io/smallrye/config/ExpressionConfigSourceInterceptorTest.java
+++ b/implementation/src/test/java/io/smallrye/config/ExpressionConfigSourceInterceptorTest.java
@@ -12,6 +12,8 @@
 import java.util.Optional;
 import java.util.stream.Stream;
 
+import jakarta.annotation.Priority;
+
 import org.junit.jupiter.api.Test;
 
 class ExpressionConfigSourceInterceptorTest {
@@ -203,10 +205,39 @@ void windowPath() {
         assertEquals("C:\\Some\\Path", config.getRawValue("window.path"));
     }
 
+    @Test
+    void nullValue() {
+        SmallRyeConfig config = buildConfigWithCustomInterceptor("sth", null);
+        ConfigValue configValue = config.getConfigValue("sth");
+
+        assertNotNull(configValue);
+
+        // No exception is thrown, only null is returned
+        assertNull(configValue.getValue());
+    }
+
     private static SmallRyeConfig buildConfig(String... keyValues) {
         return new SmallRyeConfigBuilder()
                 .addDefaultInterceptors()
                 .withSources(KeyValuesConfigSource.config(keyValues))
                 .build();
     }
+
+    private static SmallRyeConfig buildConfigWithCustomInterceptor(String... keyValues) {
+        return new SmallRyeConfigBuilder()
+                .addDefaultInterceptors()
+                .withInterceptors(new CustomConfigSourceInterceptor())
+                .withInterceptors(new ExpressionConfigSourceInterceptor())
+                .withSources(KeyValuesConfigSource.config(keyValues))
+                .build();
+    }
+
+    @Priority(Priorities.LIBRARY + 201)
+    private static class CustomConfigSourceInterceptor implements ConfigSourceInterceptor {
+
+        @Override
+        public ConfigValue getValue(ConfigSourceInterceptorContext context, String name) {
+            return ConfigValue.builder().withName(name).withValue(null).build();
+        }
+    }
 }