diff options
-rw-r--r-- | src/library/scala/collection/immutable/HashMap.scala | 2 | ||||
-rw-r--r-- | test/junit/scala/collection/immutable/HashMapTest.scala | 48 |
2 files changed, 49 insertions, 1 deletions
diff --git a/src/library/scala/collection/immutable/HashMap.scala b/src/library/scala/collection/immutable/HashMap.scala index 92d915fe8b..3e482f1369 100644 --- a/src/library/scala/collection/immutable/HashMap.scala +++ b/src/library/scala/collection/immutable/HashMap.scala @@ -197,7 +197,7 @@ object HashMap extends ImmutableMapFactory[HashMap] with BitOperations.Int { if (this.value.asInstanceOf[AnyRef] eq value.asInstanceOf[AnyRef]) this else new HashMap1(key, hash, value, kv) } else { - val nkv = merger(this.kv, kv) + val nkv = merger(this.ensurePair, if(kv != null) kv else (key, value)) new HashMap1(nkv._1, hash, nkv._2, nkv) } } else { diff --git a/test/junit/scala/collection/immutable/HashMapTest.scala b/test/junit/scala/collection/immutable/HashMapTest.scala new file mode 100644 index 0000000000..a970786455 --- /dev/null +++ b/test/junit/scala/collection/immutable/HashMapTest.scala @@ -0,0 +1,48 @@ +package scala.collection.immutable + +import org.junit.Assert.assertEquals +import org.junit.Test +import org.junit.runner.RunWith +import org.junit.runners.JUnit4 + +@RunWith(classOf[JUnit4]) +class HashMapTest { + + private val computeHashF = { + HashMap.empty.computeHash _ + } + + @Test + def canMergeIdenticalHashMap1sWithNullKvs() { + def m = new HashMap.HashMap1(1, computeHashF(1), 1, null) + val merged = m.merged(m)(null) + assertEquals(m, merged) + } + + @Test + def canMergeIdenticalHashMap1sWithNullKvsCustomMerge() { + def m = new HashMap.HashMap1(1, computeHashF(1), 1, null) + val merged = m.merged(m) { + case ((k1, v1), (k2, v2)) => + (k1, v1 + v2) + } + assertEquals(new HashMap.HashMap1(1, computeHashF(1), 2, null), merged) + } + + @Test + def canMergeHashMap1sWithNullKvsHashCollision() { + val key1 = 1000L * 1000 * 1000 * 10 + val key2 = key1.##.toLong + assert(key1.## == key2.##) + + val m1 = new HashMap.HashMap1(key1, computeHashF(key1.##), 1, null) + val m2 = new HashMap.HashMap1(key2, computeHashF(key2.##), 1, null) + val expected = HashMap(key1 -> 1, key2 -> 1) + val merged = m1.merged(m2)(null) + assertEquals(expected, merged) + val mergedWithMergeFunction = m1.merged(m2) { (kv1, kv2) => + throw new RuntimeException("Should not be reached.") + } + assertEquals(expected, mergedWithMergeFunction) + } +}
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