Do not allow writing metadata versions that are too high

because a format may be incorrect for future compilers

#KT-64230 Fixed

libraries/kotlinx-metadata/jvm/src/kotlinx/metadata/jvm/JvmMetadataVersion.kt

@@ -112,5 +112,8 @@ public class JvmMetadataVersion(public val major: Int, public val minor: Int, pu
          */
         @JvmField
         public val LATEST_STABLE_SUPPORTED: JvmMetadataVersion = JvmMetadataVersion(CompilerMetadataVersion.INSTANCE.toArray())
+
+        @JvmField
+        internal val HIGHEST_ALLOWED_TO_WRITE: JvmMetadataVersion = JvmMetadataVersion(CompilerMetadataVersion.INSTANCE_NEXT.toArray())
     }
 }

libraries/kotlinx-metadata/jvm/src/kotlinx/metadata/jvm/KotlinClassMetadata.kt

@@ -106,7 +106,7 @@ public sealed class KotlinClassMetadata {
 
         override fun write(): Metadata {
             throwIfNotWriteable(isAllowedToWrite, "class")
-            checkMetadataVersion(version)
+            checkMetadataVersionForWrite(version)
             return wrapWriteIntoIAE {
                 val writer = ClassWriter(JvmStringTable())
                 writer.writeClass(kmClass)
@@ -198,7 +198,7 @@ public sealed class KotlinClassMetadata {
 
         override fun write(): Metadata {
             throwIfNotWriteable(isAllowedToWrite, "file facade")
-            checkMetadataVersion(version)
+            checkMetadataVersionForWrite(version)
             return wrapWriteIntoIAE {
                 val writer = PackageWriter(JvmStringTable())
                 writer.writePackage(kmPackage)
@@ -286,7 +286,7 @@ public sealed class KotlinClassMetadata {
 
         override fun write(): Metadata {
             throwIfNotWriteable(isAllowedToWrite, if (isLambda) "lambda" else "synthetic class")
-            checkMetadataVersion(version)
+            checkMetadataVersionForWrite(version)
             return if (isLambda) wrapWriteIntoIAE {
                 val writer = LambdaWriter(JvmStringTable())
                 writer.writeLambda(kmLambda!!)
@@ -424,7 +424,7 @@ public sealed class KotlinClassMetadata {
 
         override fun write(): Metadata {
             throwIfNotWriteable(isAllowedToWrite, "multi-file class facade")
-            checkMetadataVersion(version)
+            checkMetadataVersionForWrite(version)
             return Metadata(
                 MULTI_FILE_CLASS_FACADE_KIND, version.toIntArray(),
                 partClassNames.toTypedArray<String>(), extraInt = flags
@@ -506,7 +506,7 @@ public sealed class KotlinClassMetadata {
 
         override fun write(): Metadata {
             throwIfNotWriteable(isAllowedToWrite, "multi-file class part")
-            checkMetadataVersion(version)
+            checkMetadataVersionForWrite(version)
             return wrapWriteIntoIAE {
                 val writer = PackageWriter(JvmStringTable())
                 writer.writePackage(kmPackage)
@@ -586,7 +586,7 @@ public sealed class KotlinClassMetadata {
 
         override fun write(): Metadata {
             throwIfNotWriteable(!lenient, "unknown kind")
-            checkMetadataVersion(version)
+            checkMetadataVersionForWrite(version)
             return Metadata(
                 original.kind,
                 version.toIntArray(),
@@ -817,11 +817,14 @@ public sealed class KotlinClassMetadata {
             throw IllegalArgumentException("This $name cannot be written because it represents metadata read in lenient mode")
         }
 
-        internal fun checkMetadataVersion(version: JvmMetadataVersion) {
+        private fun checkMetadataVersionForWrite(version: JvmMetadataVersion) {
             require(version.major >= 1 && (version.major > 1 || version.minor >= 4)) {
                 "This version of kotlinx-metadata-jvm doesn't support writing Kotlin metadata of version earlier than 1.4. " +
                         "Please change the version from $version to at least [1, 4]."
             }
+            require(version <= JvmMetadataVersion.HIGHEST_ALLOWED_TO_WRITE) {
+                "kotlinx-metadata-jvm cannot write metadata for future compiler versions. Requested to write version $version, but highest known version is ${JvmMetadataVersion.HIGHEST_ALLOWED_TO_WRITE}"
+            }
         }
 
         /**

libraries/kotlinx-metadata/jvm/test/kotlinx/metadata/test/WritersContractTest.kt

@@ -48,4 +48,22 @@ class WritersContractTest {
         assertEquals(before.extraString, after.extraString)
         assertEquals(before.packageName, after.packageName)
     }
+
+    @Test
+    fun futureVersionCantBeWritten() = everyType.forEach { before ->
+        val md = KotlinClassMetadata.readStrict(before)
+        md.version = JvmMetadataVersion(3, 4, 5)
+        assertFailsWith<IllegalArgumentException> { md.write() }
+    }
+
+    @Test
+    fun nextVersionWrite() = everyType.forEach { before ->
+        val md = KotlinClassMetadata.readStrict(before)
+        val ver = md.version
+        assertEquals(2, ver.major) // to correctly handle future case 2.x -> 3.0
+        md.version = JvmMetadataVersion(ver.major, ver.minor + 1, ver.patch)
+        md.write() // OK
+        md.version = JvmMetadataVersion(ver.major, ver.minor + 2, ver.patch)
+        assertFailsWith<IllegalArgumentException> { md.write() }
+    }
 }