Combine repository override configuration with file existence

launcher-implementation/src/main/scala/xsbt/boot/ConfigurationParser.scala

@@ -143,17 +143,13 @@ class ConfigurationParser:
     val (ivyHome, m1) = optfile(m, "ivy-home")
     val (checksums, m2) = ids(m1, "checksums", BootConfiguration.DefaultChecksums)
     val (repoConfigOverride, m3) = optfile(m2, "repository-override")
-    val (overrideRepos, m4) = bool(
-      m3,
-      "override-build-repos",
-      repoConfigOverride.exists(_.exists())
-    )
+    val repoConfigOverrideExists = repoConfigOverride.exists(_.exists())
+    val (configuredOverrideRepos, m4) = bool(m3, "override-build-repos", false)
+    val overrideRepos = configuredOverrideRepos || repoConfigOverrideExists
     val (repoConfig, m5) = optfile(m4, "repository-config")
     check(m5, "label")
     val effectiveRepoConfig =
-      if overrideRepos && repoConfigOverride.exists(_.exists())
-      then repoConfigOverride
-      else repoConfig
+      if repoConfigOverrideExists then repoConfigOverride else repoConfig
     (ivyHome, checksums, overrideRepos, effectiveRepoConfig filter (_.exists))
   def getBoot(m: LabelMap): BootSetup =
     val (dir, m1) = file(m, "directory", toFile("project/boot"))

launcher-implementation/src/test/scala/ConfigurationParserTest.scala

@@ -5,9 +5,51 @@
 
 package xsbt.boot
 
+import java.io.File
 import java.net.URI
+import java.nio.file.Files
 
 object ConfigurationParserTest extends verify.BasicTestSuite:
+  test("repository override activation combines the configured value and file existence") {
+    val directory = Files.createTempDirectory("launcher-repository-override-test").toFile
+    val repositoryConfig = new File(directory, "repositories")
+    val repositoryOverride = new File(directory, "repositories_force")
+    Files.write(repositoryConfig.toPath, "[repositories]\n  local\n".getBytes("UTF-8"))
+
+    try
+      val cases = List(
+        (false, false, false, repositoryConfig),
+        (true, false, true, repositoryConfig),
+        (false, true, true, repositoryOverride),
+        (true, true, true, repositoryOverride)
+      )
+
+      cases.foreach {
+        case (configuredOverride, overrideFileExists, expectedOverride, expectedFile) =>
+          if overrideFileExists then
+            Files.write(
+              repositoryOverride.toPath,
+              "[repositories]\n  maven-central\n".getBytes("UTF-8")
+            )
+          else Files.deleteIfExists(repositoryOverride.toPath)
+
+          val ivy =
+            ListMap[String, Option[String]](
+              "override-build-repos" -> Option(configuredOverride.toString),
+              "repository-config" -> Option(repositoryConfig.getAbsolutePath),
+              "repository-override" -> Option(repositoryOverride.getAbsolutePath)
+            ).default(_ => None)
+          val (_, _, actualOverride, actualFile) = (new ConfigurationParser).getIvy(ivy)
+
+          assert(actualOverride == expectedOverride)
+          assert(actualFile.contains(expectedFile))
+      }
+    finally
+      Files.deleteIfExists(repositoryOverride.toPath)
+      Files.deleteIfExists(repositoryConfig.toPath)
+      Files.deleteIfExists(directory.toPath)
+  }
+
   test("Configuration parser should correct parse bootOnly") {
     repoFileContains(
       """|[repositories]