Proper support for stashing on-failure handlers. Fixes #732.

main/command/src/main/scala/sbt/BasicCommandStrings.scala

@@ -110,6 +110,9 @@ AliasCommand + """ name=
 	def Shell = "shell"
 	def ShellDetailed = "Provides an interactive prompt from which commands can be run."
 
+	def StashOnFailure = "sbtStashOnFailure"
+	def PopOnFailure = "sbtPopOnFailure"
+
 	def ClearOnFailure = "--"
 	def OnFailure = "-"
 	def OnFailureDetailed =

main/command/src/main/scala/sbt/BasicCommands.scala

@@ -16,7 +16,7 @@ package sbt
 
 object BasicCommands
 {
-	lazy val allBasicCommands = Seq(nop, ignore, help, multi, ifLast, append, setOnFailure, clearOnFailure, reboot, call, exit, continuous, history, shell, read, alias)
+	lazy val allBasicCommands = Seq(nop, ignore, help, multi, ifLast, append, setOnFailure, clearOnFailure, stashOnFailure, popOnFailure, reboot, call, exit, continuous, history, shell, read, alias)
 
 	def nop = Command.custom(s => success(() => s))
 	def ignore = Command.command(FailureWall)(idFun)
@@ -74,6 +74,12 @@ object BasicCommands
 		s.copy(onFailure = Some(arg))
 	}
 	def clearOnFailure = Command.command(ClearOnFailure)(s => s.copy(onFailure = None))
+	def stashOnFailure = Command.command(StashOnFailure)(s => s.copy(onFailure = None).update(OnFailureStack)(s.onFailure :: _.toList.flatten))
+	def popOnFailure = Command.command(PopOnFailure) { s =>
+		val stack = s.get(OnFailureStack).getOrElse(Nil)
+		val updated = if(stack.isEmpty) s.remove(OnFailureStack) else s.put(OnFailureStack, stack.tail)
+		updated.copy(onFailure = stack.headOption.flatten)
+	}
 
 	def reboot = Command(RebootCommand, Help.more(RebootCommand, RebootDetailed))(rebootParser) { (s, full) =>
 		s.reboot(full)

main/command/src/main/scala/sbt/BasicKeys.scala

@@ -9,4 +9,5 @@ object BasicKeys
 	val watch = AttributeKey[Watched]("watch", "Continuous execution configuration.", 1000)
 	private[sbt] val interactive = AttributeKey[Boolean]("interactive", "True if commands are currently being entered from an interactive environment.", 10)
 	private[sbt] val classLoaderCache = AttributeKey[classpath.ClassLoaderCache]("class-loader-cache", "Caches class loaders based on the classpath entries and last modified times.", 10)
+	private[sbt] val OnFailureStack = AttributeKey[List[Option[String]]]("on-failure-stack", "Stack that remembers on-failure handlers.", 10)
 }

main/command/src/main/scala/sbt/State.scala

@@ -121,6 +121,7 @@ trait StateOps {
 
 object State
 {
+	/** Indicates where command execution should resume after a failure.*/
 	final val FailureWall = "---"
 
 	/** Represents the next action for the command processor.*/

main/src/main/scala/sbt/Main.scala

@@ -77,7 +77,8 @@ object BuiltinCommands
 	def ScriptCommands: Seq[Command] = Seq(ignore, exit, Script.command, act, nop)
 	def DefaultCommands: Seq[Command] = Seq(ignore, help, about, tasks, settingsCommand, loadProject,
 		projects, project, reboot, read, history, set, sessionCommand, inspect, loadProjectImpl, loadFailed, Cross.crossBuild, Cross.switchVersion,
-		setOnFailure, clearOnFailure, ifLast, multi, shell, continuous, eval, alias, append, last, lastGrep, export, boot, nop, call, exit, act)
+		setOnFailure, clearOnFailure, stashOnFailure, popOnFailure,
+		ifLast, multi, shell, continuous, eval, alias, append, last, lastGrep, export, boot, nop, call, exit, act)
 	def DefaultBootCommands: Seq[String] = LoadProject :: (IfLast + " " + Shell) :: Nil
 
 	def boot = Command.make(BootCommand)(bootParser)
@@ -415,7 +416,13 @@ object BuiltinCommands
 		}
 	}
 
-	def loadProjectCommands(arg: String) = (OnFailure + " " + LoadFailed) :: (LoadProjectImpl + " " + arg).trim :: ClearOnFailure :: State.FailureWall :: Nil
+	def loadProjectCommands(arg: String) =
+		StashOnFailure ::
+		(OnFailure + " " + LoadFailed) ::
+		(LoadProjectImpl + " " + arg).trim ::
+		PopOnFailure ::
+		State.FailureWall ::
+		Nil
 	def loadProject = Command(LoadProject, LoadProjectBrief, LoadProjectDetailed)(_ => matched(Project.loadActionParser)) { (s,arg) => loadProjectCommands(arg) ::: s }
 
 	def loadProjectImpl = Command(LoadProjectImpl)(_ => Project.loadActionParser)( doLoadProject )

sbt/src/sbt-test/actions/multiple-with-error/test

@@ -0,0 +1,3 @@
+# Issue 732: reload followed by a command that results in an error exits in interactive mode
+-> ;reload;not-a-command
+> help