Allow Git pushes without tracking branch.

src/main/scala/ReleaseExtra.scala

@@ -214,9 +214,6 @@ object ReleaseStateTransformations {
 
   lazy val pushChanges: ReleaseStep = ReleaseStep(pushChangesAction, checkUpstream)
   private[sbtrelease] lazy val checkUpstream = { st: State =>
-    if (!vcs(st).hasUpstream) {
-      sys.error("No tracking branch is set up. Either configure a remote tracking branch, or remove the pushChanges release part.")
-    }
     val defaultChoice = extractDefault(st, "n")
 
     st.log.info("Checking remote [%s] ..." format vcs(st).trackingRemote)
@@ -240,18 +237,14 @@ object ReleaseStateTransformations {
     val defaultChoice = extractDefault(st, "y")
 
     val vc = vcs(st)
-    if (vc.hasUpstream) {
-      defaultChoice orElse SimpleReader.readLine("Push changes to the remote repository (y/n)? [y] ") match {
-        case Yes() | Some("") =>
-          val processLogger: ProcessLogger = if (vc.isInstanceOf[Git]) {
-            // Git outputs to standard error, so use a logger that redirects stderr to info
-            vc.stdErrorToStdOut(st.log)
-          } else st.log
-          vc.pushChanges !! processLogger
-        case _ => st.log.warn("Remember to push the changes yourself!")
-      }
-    } else {
-      st.log.info("Changes were NOT pushed, because no upstream branch is configured for the local branch [%s]" format vcs(st).currentBranch)
+    defaultChoice orElse SimpleReader.readLine("Push changes to the remote repository (y/n)? [y] ") match {
+      case Yes() | Some("") =>
+        val processLogger: ProcessLogger = if (vc.isInstanceOf[Git]) {
+          // Git outputs to standard error, so use a logger that redirects stderr to info
+          vc.stdErrorToStdOut(st.log)
+        } else st.log
+        vc.pushChanges !! processLogger
+      case _ => st.log.warn("Remember to push the changes yourself!")
     }
     st
   }

src/main/scala/Vcs.scala

@@ -16,7 +16,6 @@ trait Vcs {
   def existsTag(name: String): Boolean
   def checkRemote(remote: String): ProcessBuilder
   def tag(name: String, comment: String, sign: Boolean): ProcessBuilder
-  def hasUpstream: Boolean
   def trackingRemote: String
   def isBehindRemote: Boolean
   def pushChanges: ProcessBuilder
@@ -96,8 +95,6 @@ class Mercurial(val baseDir: File) extends Vcs with GitLike {
   def tag(name: String, comment: String, sign: Boolean) =
     andSign(sign, cmd("tag", "-f", "-m", comment, name))
 
-  def hasUpstream = cmd("paths", "default") ! devnull == 0
-
   def trackingRemote = "default"
 
   def isBehindRemote = cmd("incoming", "-b", ".", "-q") ! devnull == 0
@@ -125,20 +122,30 @@ class Git(val baseDir: File) extends Vcs with GitLike {
 
 
   private lazy val trackingBranchCmd = cmd("config", "branch.%s.merge" format currentBranch)
-  private def trackingBranch: String = (trackingBranchCmd !!).trim.stripPrefix("refs/heads/")
+  private def trackingBranch: String = try {
+    (trackingBranchCmd !!).trim.stripPrefix("refs/heads/")
+  } catch {
+    case _: Throwable => currentBranch
+  }
 
   private lazy val trackingRemoteCmd: ProcessBuilder = cmd("config", "branch.%s.remote" format currentBranch)
-  def trackingRemote: String = (trackingRemoteCmd !!) trim
-
-  def hasUpstream = trackingRemoteCmd ! devnull == 0 && trackingBranchCmd ! devnull == 0
+  def trackingRemote: String = try {
+    (trackingRemoteCmd !!).trim
+  } catch {
+    case _: Throwable => "origin"
+  }
 
   def currentBranch =  (cmd("symbolic-ref", "HEAD") !!).trim.stripPrefix("refs/heads/")
 
   def currentHash = revParse("HEAD")
 
   private def revParse(name: String) = (cmd("rev-parse", name) !!) trim
 
-  def isBehindRemote = (cmd("rev-list", "%s..%s/%s".format(currentBranch, trackingRemote, trackingBranch)) !! devnull).trim.nonEmpty
+  def isBehindRemote = try {
+    (cmd("rev-list", "%s..%s/%s".format(currentBranch, trackingRemote, trackingBranch)) !! devnull).trim.nonEmpty
+  } catch {
+    case _: Throwable => false
+  }
 
   private def withSignFlag(sign: Boolean, flag: String)(args: String*) =
     if (sign)
@@ -207,8 +214,6 @@ class Subversion(val baseDir: File) extends Vcs {
 
   override def trackingRemote: String = ""
 
-  override def hasUpstream: Boolean = true
-
   override def tag(name: String, comment: String, sign: Boolean): ProcessBuilder = {
     require(!sign, "Signing not supported in Subversion.")
     val tagUrl = getSvnTagUrl(name)
@@ -256,4 +261,4 @@ class Subversion(val baseDir: File) extends Vcs {
 
 private[sbtrelease] object Try {
   def apply[A](f: => A): Option[A] = scala.util.control.Exception.allCatch.opt(f)
-}
+}