Let ClassBytesRepository ignore invalid classpath entries

subprojects/provider/src/main/kotlin/org/gradle/kotlin/dsl/support/ClassBytesRepository.kt

@@ -85,10 +85,10 @@ class ClassBytesRepository(classPath: ClassPath, classPathDependencies: ClassPat
         classBytesIndex.firstNotNullResult { it(classFilePath) }
 
     private
-    fun sourceNamesFrom(jarOrDir: File): Sequence<String> =
+    fun sourceNamesFrom(entry: File): Sequence<String> =
         when {
-            jarOrDir.isFile -> sourceNamesFromJar(jarOrDir)
-            jarOrDir.isDirectory -> sourceNamesFromDir(jarOrDir)
+            entry.isClassPathArchive -> sourceNamesFromJar(entry)
+            entry.isDirectory -> sourceNamesFromDir(entry)
             else -> emptySequence()
         }
 
@@ -107,10 +107,10 @@ class ClassBytesRepository(classPath: ClassPath, classPathDependencies: ClassPat
             .map { kotlinSourceNameOf(normaliseFileSeparators(it.relativeTo(dir).path)) }
 
     private
-    fun classBytesIndexFor(jarOrDir: File): ClassBytesIndex =
+    fun classBytesIndexFor(entry: File): ClassBytesIndex =
         when {
-            jarOrDir.isFile -> jarClassBytesIndexFor(jarOrDir)
-            jarOrDir.isDirectory -> directoryClassBytesIndexFor(jarOrDir)
+            entry.isClassPathArchive -> jarClassBytesIndexFor(entry)
+            entry.isDirectory -> directoryClassBytesIndexFor(entry)
             else -> { _ -> null }
         }
 
@@ -138,6 +138,14 @@ class ClassBytesRepository(classPath: ClassPath, classPathDependencies: ClassPat
 }
 
 
+/**
+ * See https://docs.oracle.com/javase/8/docs/technotes/tools/findingclasses.html#userclass
+ */
+private
+val File.isClassPathArchive
+    get() = extension.run { equals("jar", ignoreCase = true) || equals("zip", ignoreCase = true) }
+
+
 private
 val String.isClassFilePath
     get() = endsWith(classFileExtension)

subprojects/provider/src/test/kotlin/org/gradle/kotlin/dsl/support/ClassBytesRepositoryTest.kt

@@ -21,6 +21,8 @@ import org.gradle.api.tasks.wrapper.Wrapper
 
 import org.gradle.kotlin.dsl.fixtures.AbstractIntegrationTest
 import org.gradle.kotlin.dsl.fixtures.DeepThought
+import org.gradle.kotlin.dsl.fixtures.LightThought
+import org.gradle.kotlin.dsl.fixtures.ZeroThought
 import org.gradle.kotlin.dsl.fixtures.customInstallation
 
 import org.hamcrest.CoreMatchers.equalTo
@@ -142,6 +144,24 @@ class ClassBytesRepositoryTest : AbstractIntegrationTest() {
         }
     }
 
+    @Test
+    fun `ignores invalid classpath entries`() {
+
+        val entries = listOf(
+            withClassJar("some.JAR", DeepThought::class.java),
+            withClassJar("some.zip", LightThought::class.java),
+            withClassJar("some.tar.gz", ZeroThought::class.java),
+            withFile("some.xml")
+        )
+
+        classPathBytesRepositoryFor(entries).use { repository ->
+            assertThat(
+                repository.allSourceNames,
+                equalTo(listOf(canonicalNameOf<DeepThought>(), canonicalNameOf<LightThought>()))
+            )
+        }
+    }
+
     private
     val ClassBytesRepository.allSourceNames: List<String>
         get() = allClassesBytesBySourceName().map { it.first }.toList()