Use constant timestamps for shadowed sources JAR entries

src/main/kotlin/com/github/jengelman/gradle/plugins/shadow/internal/ShadowedSourcesJar.kt

@@ -20,7 +20,6 @@ internal fun generateSourcesJar(
   dependencies: Iterable<File>,
   relocators: Iterable<Relocator>,
   unusedClasses: Set<String>,
-  preserveFileTimestamps: Boolean,
 ) =
   try {
     zipOutStream.use { zos ->
@@ -36,11 +35,7 @@ internal fun generateSourcesJar(
 
       val manifestEntry = "META-INF/MANIFEST.MF"
       visitedFiles.add(manifestEntry)
-      zos.writeEntry(
-        name = manifestEntry,
-        preserveLastModified = preserveFileTimestamps,
-        unixMode = UnixMode.file(),
-      ) {
+      zos.writeEntry(name = manifestEntry, unixMode = UnixMode.file()) {
         write("Manifest-Version: 1.0\n\n".toByteArray())
       }
 
@@ -54,19 +49,12 @@ internal fun generateSourcesJar(
       runBlocking {
         val parallelWriter = OrderedParallelWriter(this)
 
-        fun writeToZip(entryName: String, lastModified: Long, bytes: ByteArray) {
-          zos.writeEntry(
-            name = entryName,
-            preserveLastModified = preserveFileTimestamps,
-            lastModified = lastModified,
-            unixMode = UnixMode.file(),
-          ) {
-            write(bytes)
-          }
+        fun writeToZip(entryName: String, bytes: ByteArray) {
+          zos.writeEntry(name = entryName, unixMode = UnixMode.file()) { write(bytes) }
         }
 
         // Relocates and writes a project or dependency source file, or a resource.
-        fun addEntry(name: String, lastModified: Long, readBytes: () -> ByteArray) {
+        fun addEntry(name: String, readBytes: () -> ByteArray) {
           if (name.isModuleInfo) return
           val isSource = name.isSourceFile()
           if (isSource && isUnused(name, unusedClasses, sourceToClasses)) return
@@ -76,7 +64,7 @@ internal fun generateSourcesJar(
           if (!isSource) {
             // Resources gain nothing from parallelism, write them directly to avoid buffering.
             parallelWriter.flush()
-            writeToZip(relocatedPath, lastModified, readBytes())
+            writeToZip(relocatedPath, readBytes())
             return
           }
           val rawBytes = readBytes()
@@ -86,14 +74,14 @@ internal fun generateSourcesJar(
                 .remapSourceFile(rawBytes.decodeToString(), name, relocatedPath)
                 .toByteArray()
             },
-            write = { writeToZip(relocatedPath, lastModified, it) },
+            write = { writeToZip(relocatedPath, it) },
           )
         }
 
         filesWithRelPaths
           .sortedBy { it.second }
           .forEach { (file, relPath) ->
-            addEntry(relPath, file.lastModified()) { file.readBytes() }
+            addEntry(relPath) { file.readBytes() }
           }
 
         sourcesJars.forEach { jarFile ->
@@ -111,26 +99,15 @@ internal fun generateSourcesJar(
               }
               .sortedBy { it.name }
               .forEach { entry ->
-                addEntry(entry.name, entry.time) { getInputStream(entry).use { it.readBytes() } }
+                addEntry(entry.name) { getInputStream(entry).use { it.readBytes() } }
               }
           }
         }
 
         parallelWriter.flush()
       }
 
-      val entries = zos.entries.map { it.name }
-      val added = entries.toMutableSet()
-      entries.forEach { name ->
-        name.parentDirectoryEntries().forEach { entryName ->
-          if (!added.add(entryName)) return@forEach
-          zos.writeEntry(
-            name = entryName,
-            preserveLastModified = preserveFileTimestamps,
-            unixMode = UnixMode.directory(),
-          )
-        }
-      }
+      zos.writeParentDirectoryEntries()
     }
   } catch (e: Exception) {
     sourcesJarFile.delete()

src/main/kotlin/com/github/jengelman/gradle/plugins/shadow/internal/Zip.kt

@@ -8,6 +8,7 @@ import org.apache.tools.zip.UnixStat
 import org.apache.tools.zip.Zip64Mode
 import org.apache.tools.zip.ZipEntry
 import org.apache.tools.zip.ZipOutputStream
+import org.gradle.api.file.FileCopyDetails
 import org.gradle.api.tasks.bundling.ZipEntryCompression
 
 @JvmInline
@@ -103,6 +104,38 @@ internal inline fun ZipOutputStream.writeEntry(
   }
 }
 
+/**
+ * Writes the missing parent directory entries of all written entries, taking the timestamp and
+ * permissions from [visitedDirs] when available.
+ */
+internal fun ZipOutputStream.writeParentDirectoryEntries(
+  preserveLastModified: Boolean = false,
+  visitedDirs: Map<String, FileCopyDetails> = emptyMap(),
+) {
+  val entries = entries.map { it.name }
+  val added = entries.toMutableSet()
+  val currentTimeMillis = System.currentTimeMillis()
+
+  entries.forEach { name ->
+    name.parentDirectoryEntries().asReversed().forEach { entryName ->
+      if (!added.add(entryName)) return@forEach
+      val details = visitedDirs[entryName.removeSuffix("/")]
+      val (lastModified, unixMode) =
+        if (details == null) {
+          currentTimeMillis to UnixMode.directory()
+        } else {
+          details.lastModified to UnixMode.directory(details.permissions.toUnixNumeric())
+        }
+      writeEntry(
+        name = entryName,
+        preserveLastModified = preserveLastModified,
+        lastModified = lastModified,
+        unixMode = unixMode,
+      )
+    }
+  }
+}
+
 internal fun String.parentDirectoryEntries(): List<String> {
   val parents = mutableListOf<String>()
   var parent = substringBeforeLast('/', "")

src/main/kotlin/com/github/jengelman/gradle/plugins/shadow/tasks/ShadowCopyAction.kt

@@ -9,10 +9,10 @@ import com.github.jengelman.gradle.plugins.shadow.internal.UnixMode
 import com.github.jengelman.gradle.plugins.shadow.internal.entries
 import com.github.jengelman.gradle.plugins.shadow.internal.gradleError
 import com.github.jengelman.gradle.plugins.shadow.internal.inputStream
-import com.github.jengelman.gradle.plugins.shadow.internal.parentDirectoryEntries
 import com.github.jengelman.gradle.plugins.shadow.internal.readBytes
 import com.github.jengelman.gradle.plugins.shadow.internal.remapClass
 import com.github.jengelman.gradle.plugins.shadow.internal.writeEntry
+import com.github.jengelman.gradle.plugins.shadow.internal.writeParentDirectoryEntries
 import com.github.jengelman.gradle.plugins.shadow.relocation.Relocator
 import com.github.jengelman.gradle.plugins.shadow.relocation.relocatePath
 import com.github.jengelman.gradle.plugins.shadow.transformers.ResourceTransformer
@@ -83,7 +83,7 @@ internal constructor(
         }
 
         processTransformers(zos)
-        addDirs(zos)
+        zos.writeParentDirectoryEntries(isPreserveFileTimestamps, visitedDirs)
         checkDuplicateEntries(zos)
       }
     } catch (e: Exception) {
@@ -118,31 +118,6 @@ internal constructor(
     }
   }
 
-  private fun addDirs(zos: ZipOutputStream) {
-    val entries = zos.entries.map { it.name }
-    val added = entries.toMutableSet()
-    val currentTimeMillis = System.currentTimeMillis()
-
-    entries.forEach { name ->
-      name.parentDirectoryEntries().asReversed().forEach { entryName ->
-        if (!added.add(entryName)) return@forEach
-        val details = visitedDirs[entryName.removeSuffix("/")]
-        val (lastModified, unixMode) =
-          if (details == null) {
-            currentTimeMillis to UnixMode.directory()
-          } else {
-            details.lastModified to UnixMode.directory(details.permissions.toUnixNumeric())
-          }
-        zos.writeEntry(
-          name = entryName,
-          preserveLastModified = isPreserveFileTimestamps,
-          lastModified = lastModified,
-          unixMode = unixMode,
-        )
-      }
-    }
-  }
-
   private fun checkDuplicateEntries(zos: ZipOutputStream) {
     val entries = zos.entries.map { it.name }
     val duplicates = entries.groupingBy { it }.eachCount().filter { it.value > 1 }

src/main/kotlin/com/github/jengelman/gradle/plugins/shadow/tasks/ShadowJar.kt

@@ -210,6 +210,9 @@ public abstract class ShadowJar : Jar() {
    * `java.withSourcesJar()` is enabled, and `false` otherwise. In projects applying the `shadow`
    * plugin for Kotlin Multiplatform, this convention defaults to `true` when sources publishing is
    * enabled on the JVM target, and `false` otherwise.
+   *
+   * Entries in the shadowed sources JAR always use [CONSTANT_TIME_FOR_ZIP_ENTRIES] as their
+   * timestamp, regardless of [isPreserveFileTimestamps].
    */
   @get:Input
   @get:Option(
@@ -846,7 +849,6 @@ public abstract class ShadowJar : Jar() {
       dependencies = includedDependencies.files,
       relocators = relocators.get() + packageRelocators,
       unusedClasses = unusedClasses,
-      preserveFileTimestamps = isPreserveFileTimestamps,
     )
   }
 

src/test/kotlin/com/github/jengelman/gradle/plugins/shadow/internal/ShadowedSourcesJarTest.kt

@@ -120,8 +120,8 @@ class ShadowedSourcesJarTest {
         "META-INF/",
         "a/",
         "m/",
-        "z/",
         "z/sub/",
+        "z/",
       )
     }
   }
@@ -269,10 +269,10 @@ class ShadowedSourcesJarTest {
         "shaded/dep/Dep.java",
         "shaded/dep/resource.txt",
         "META-INF/",
-        "com/",
         "com/example/",
-        "shaded/",
+        "com/",
         "shaded/dep/",
+        "shaded/",
       )
       getContent("shaded/dep/Dep.java").isEqualTo("package shaded.dep;\npublic class Dep {}")
       getContent("shaded/dep/resource.txt").isEqualTo("dep resource")
@@ -306,8 +306,8 @@ class ShadowedSourcesJarTest {
         "META-INF/MANIFEST.MF",
         *expectedEntries.toTypedArray(),
         "META-INF/",
-        "shaded/",
         "shaded/example/",
+        "shaded/",
       )
       names.forEach { name ->
         getContent("shaded/example/$name.java")
@@ -339,5 +339,4 @@ private fun generateSourcesJar(
     dependencies = emptyList(),
     relocators = relocators,
     unusedClasses = emptySet(),
-    preserveFileTimestamps = true,
   )