fix: enforce last-value-wins in AttributesMap for duplicate keys of different types

sdk/common/src/main/java/io/opentelemetry/sdk/common/internal/AttributesMap.java

@@ -63,12 +63,29 @@ public Object put(AttributeKey<?> key, @Nullable Object value) {
       return null;
     }
     totalAddedValues++;
+    AttributeKey<?> existingKey = null;
+    for (AttributeKey<?> k : keySet()) {
+      if (k.getKey().equals(key.getKey())) {
+        existingKey = k;
+        break;
+      }
+    }
+    if (existingKey != null && !existingKey.equals(key)) {
+      super.remove(existingKey);
+    }
     if (size() >= capacity && !containsKey(key)) {
       return null;
     }
     return super.put(key, AttributeUtil.applyAttributeLengthLimit(value, lengthLimit));
   }
 
+  @Override
+  public void putAll(Map<? extends AttributeKey<?>, ?> m) {
+    for (Map.Entry<? extends AttributeKey<?>, ?> entry : m.entrySet()) {
+      put(entry.getKey(), entry.getValue());
+    }
+  }
+
   /** Generic overload of {@link #put(AttributeKey, Object)}. */
   public <T> void putIfCapacity(AttributeKey<T> key, @Nullable T value) {
     put(key, value);

sdk/common/src/test/java/io/opentelemetry/sdk/common/internal/AttributesMapTest.java

@@ -5,10 +5,15 @@
 
 package io.opentelemetry.sdk.common.internal;
 
+import static io.opentelemetry.api.common.AttributeKey.booleanKey;
 import static io.opentelemetry.api.common.AttributeKey.longKey;
+import static io.opentelemetry.api.common.AttributeKey.stringKey;
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.entry;
 
+import io.opentelemetry.api.common.AttributeKey;
+import java.util.HashMap;
+import java.util.Map;
 import org.junit.jupiter.api.Test;
 
 class AttributesMapTest {
@@ -22,4 +27,34 @@ void asMap() {
     assertThat(attributesMap.asMap())
         .containsOnly(entry(longKey("one"), 1L), entry(longKey("two"), 2L));
   }
+
+  @Test
+  void put_lastValueWins_differentTypes() {
+    AttributesMap attributesMap = AttributesMap.create(10, Integer.MAX_VALUE);
+    attributesMap.put(stringKey("key"), "value");
+    attributesMap.put(booleanKey("key"), false);
+
+    assertThat(attributesMap.asMap()).containsOnly(entry(booleanKey("key"), false));
+  }
+
+  @Test
+  void put_lastValueWins_sameType() {
+    AttributesMap attributesMap = AttributesMap.create(10, Integer.MAX_VALUE);
+    attributesMap.put(stringKey("key"), "value1");
+    attributesMap.put(stringKey("key"), "value2");
+
+    assertThat(attributesMap.asMap()).containsOnly(entry(stringKey("key"), "value2"));
+  }
+
+  @Test
+  void putAll() {
+    AttributesMap attributesMap = AttributesMap.create(10, Integer.MAX_VALUE);
+    Map<AttributeKey<?>, Object> newAttrs = new HashMap<>();
+    newAttrs.put(stringKey("key1"), "value1");
+    newAttrs.put(booleanKey("key2"), true);
+    attributesMap.putAll(newAttrs);
+
+    assertThat(attributesMap.asMap())
+        .containsOnly(entry(stringKey("key1"), "value1"), entry(booleanKey("key2"), true));
+  }
 }