diff --git a/src/Pure/Admin/other_isabelle.scala b/src/Pure/Admin/other_isabelle.scala
--- a/src/Pure/Admin/other_isabelle.scala
+++ b/src/Pure/Admin/other_isabelle.scala
@@ -1,113 +1,121 @@
 /*  Title:      Pure/Admin/other_isabelle.scala
     Author:     Makarius
 
 Manage other Isabelle distributions.
 */
 
 package isabelle
 
 
 object Other_Isabelle {
   def apply(isabelle_home: Path,
       isabelle_identifier: String = "",
       user_home: Path = Path.USER_HOME,
       progress: Progress = new Progress): Other_Isabelle =
     new Other_Isabelle(isabelle_home.canonical, isabelle_identifier, user_home, progress)
 }
 
 final class Other_Isabelle private(
   val isabelle_home: Path,
   val isabelle_identifier: String,
   user_home: Path,
   progress: Progress
 ) {
   other_isabelle =>
 
   override def toString: String = isabelle_home.toString
 
-  if (proper_string(System.getenv("ISABELLE_SETTINGS_PRESENT")).isDefined)
+  if (proper_string(System.getenv("ISABELLE_SETTINGS_PRESENT")).isDefined) {
     error("Cannot initialize with enclosing ISABELLE_SETTINGS_PRESENT")
+  }
 
 
   /* static system */
 
   def bash(
-      script: String,
-      redirect: Boolean = false,
-      echo: Boolean = false,
-      strict: Boolean = true): Process_Result =
+    script: String,
+    redirect: Boolean = false,
+    echo: Boolean = false,
+    strict: Boolean = true
+  ): Process_Result = {
     progress.bash(
       "export USER_HOME=" + File.bash_path(user_home) + "\n" +
       Isabelle_System.export_isabelle_identifier(isabelle_identifier) + script,
       env = null, cwd = isabelle_home.file, redirect = redirect, echo = echo, strict = strict)
+  }
 
   def apply(
-      cmdline: String,
-      redirect: Boolean = false,
-      echo: Boolean = false,
-      strict: Boolean = true): Process_Result =
+    cmdline: String,
+    redirect: Boolean = false,
+    echo: Boolean = false,
+    strict: Boolean = true
+  ): Process_Result = {
     bash("bin/isabelle " + cmdline, redirect = redirect, echo = echo, strict = strict)
+  }
 
-  def resolve_components(echo: Boolean): Unit =
+  def resolve_components(echo: Boolean): Unit = {
     other_isabelle(
       "env ISABELLE_TOOLS=" + Bash.string(Isabelle_System.getenv("ISABELLE_TOOLS")) +
       " isabelle components -a", redirect = true, echo = echo).check
+  }
 
   def getenv(name: String): String =
     other_isabelle("getenv -b " + Bash.string(name)).check.out
 
   val isabelle_home_user: Path = Path.explode(getenv("ISABELLE_HOME_USER"))
 
   val etc: Path = isabelle_home_user + Path.explode("etc")
   val etc_settings: Path = etc + Path.explode("settings")
   val etc_preferences: Path = etc + Path.explode("preferences")
 
 
   /* components */
 
   def init_components(
     component_repository: String = Components.default_component_repository,
     components_base: Path = Components.default_components_base,
     catalogs: List[String] = Nil,
     components: List[String] = Nil
   ): List[String] = {
     val dir = Components.admin(isabelle_home)
 
     ("ISABELLE_COMPONENT_REPOSITORY=" + Bash.string(component_repository)) ::
     catalogs.map(name =>
       "init_components " + File.bash_path(components_base) + " " +
         File.bash_path(dir + Path.basic(name))) :::
     components.map(name =>
       "init_component " + File.bash_path(components_base + Path.basic(name)))
   }
 
 
   /* settings */
 
   def clean_settings(): Boolean =
     if (!etc_settings.is_file) true
     else if (File.read(etc_settings).startsWith("# generated by Isabelle")) {
-      etc_settings.file.delete; true
+      etc_settings.file.delete
+      true
     }
     else false
 
   def init_settings(settings: List[String]): Unit = {
-    if (!clean_settings())
+    if (!clean_settings()) {
       error("Cannot proceed with existing user settings file: " + etc_settings)
+    }
 
     Isabelle_System.make_directory(etc_settings.dir)
     File.write(etc_settings,
       "# generated by Isabelle " + Date.now() + "\n" +
       "#-*- shell-script -*- :mode=shellscript:\n" +
       settings.mkString("\n", "\n", "\n"))
   }
 
 
   /* cleanup */
 
   def cleanup(): Unit = {
     clean_settings()
     etc.file.delete
     isabelle_home_user.file.delete
   }
 }