back all ConsoleLoggers by a common ConsoleOut

The common ConsoleOut merges (overwrites) consecutive Resolving xxxx ... lines
when ansi codes are enabled.

util/log/ConsoleLogger.scala

@@ -8,6 +8,29 @@ package sbt
 object ConsoleLogger
 {
 	def systemOut: ConsoleOut = printStreamOut(System.out)
+	def overwriteContaining(s: String): (String,String) => Boolean = (cur, prev) =>
+		cur.contains(s) && prev.contains(s)
+
+	/** ConsoleOut instance that is backed by System.out.  It overwrites the previously printed line
+	* if the function `f(lineToWrite, previousLine)` returns true.
+	*
+	* The ConsoleOut returned by this method assumes that the only newlines are from println calls
+	* and not in the String arguments. */
+	def systemOutOverwrite(f: (String,String) => Boolean): ConsoleOut = new ConsoleOut {
+		val lockObject = System.out
+		private[this] var last: Option[String] = None
+		private[this] var current = new java.lang.StringBuffer
+		def print(s: String): Unit = synchronized { current.append(s) }
+		def println(s: String): Unit = synchronized { current.append(s); println() }
+		def println(): Unit = synchronized {
+			val s = current.toString
+			if(formatEnabled && last.exists(lmsg => f(s, lmsg)))
+				System.out.print(OverwriteLine)
+			System.out.println(s)
+			last = Some(s)
+			current = new java.lang.StringBuffer
+		}
+	}
 	def printStreamOut(out: PrintStream): ConsoleOut = new ConsoleOut {
 		val lockObject = out
 		def print(s: String) = out.print(s)
@@ -30,6 +53,9 @@ object ConsoleLogger
 	/** Escape character, used to introduce an escape sequence. */
 	final val ESC = '\u001B'
 
+	/** Move to beginning of previous line and clear the line. */
+	private[sbt] final val OverwriteLine = "\r\u001BM\u001B[2K"
+
 	/** An escape terminator is a character in the range `@` (decimal value 64) to `~` (decimal value 126). 
 	* It is the final character in an escape sequence. */
 	def isEscapeTerminator(c: Char): Boolean =

util/log/GlobalLogging.scala

@@ -19,9 +19,12 @@ object GlobalLogBacking
 }
 object GlobalLogging
 {
+	@deprecated("Explicitly specify standard out.", "0.13.0")
 	def initial(newLogger: (PrintWriter, GlobalLogBacking) => GlobalLogging, newBackingFile: => File): GlobalLogging =
+		initial(newLogger, newBackingFile, ConsoleLogger.systemOut)
+	def initial(newLogger: (PrintWriter, GlobalLogBacking) => GlobalLogging, newBackingFile: => File, console: ConsoleOut): GlobalLogging =
 	{
-		val log = ConsoleLogger()
+		val log = ConsoleLogger(console)
 		GlobalLogging(log, log, GlobalLogBacking(newLogger, newBackingFile))
 	}
 }

util/log/MainLogging.scala

@@ -18,17 +18,29 @@ object MainLogging
 		multi: Logger
 	}
 	def globalDefault(writer: PrintWriter, backing: GlobalLogBacking): GlobalLogging =
+		globalDefault(writer, backing, ConsoleLogger.systemOut)
+	def globalDefault(writer: PrintWriter, backing: GlobalLogBacking, console: ConsoleOut): GlobalLogging =
 	{
 		val backed = defaultBacked()(writer)
-		val full = multiLogger(defaultMultiConfig( backed ) )
+		val full = multiLogger(defaultMultiConfig(console, backed ) )
 		GlobalLogging(full, backed, backing)
 	}
 
+	@deprecated("Explicitly specify the console output.", "0.13.0")
 	def defaultMultiConfig(backing: AbstractLogger): MultiLoggerConfig =
-		new MultiLoggerConfig(defaultScreen(ConsoleLogger.noSuppressedMessage), backing, Nil, Level.Info, Level.Debug, -1, Int.MaxValue)
+		defaultMultiConfig(ConsoleLogger.systemOut, backing)
+	def defaultMultiConfig(console: ConsoleOut, backing: AbstractLogger): MultiLoggerConfig =
+		new MultiLoggerConfig(defaultScreen(console, ConsoleLogger.noSuppressedMessage), backing, Nil, Level.Info, Level.Debug, -1, Int.MaxValue)
 
+	@deprecated("Explicitly specify the console output.", "0.13.0")
 	def defaultScreen(): AbstractLogger = ConsoleLogger()
+
+	@deprecated("Explicitly specify the console output.", "0.13.0")
 	def defaultScreen(suppressedMessage: SuppressedTraceContext => Option[String]): AbstractLogger = ConsoleLogger(suppressedMessage = suppressedMessage)
+
+	def defaultScreen(console: ConsoleOut): AbstractLogger = ConsoleLogger(console)
+	def defaultScreen(console: ConsoleOut, suppressedMessage: SuppressedTraceContext => Option[String]): AbstractLogger =
+		ConsoleLogger(console, suppressedMessage = suppressedMessage)
 	
 	def defaultBacked(useColor: Boolean = ConsoleLogger.formatEnabled): PrintWriter => ConsoleLogger =
 		to => ConsoleLogger(ConsoleLogger.printWriterOut(to), useColor = useColor)