Reinstated old, trusted starr from r17713.

Modified version number detection, so that
until we have a new starr both 4 and 5 are
acceptable (without warnings).

Restored stability test so that it does
complain if differences are found; however,
a failed stability test is still non-fatal
for the time being.



git-svn-id: http://lampsvn.epfl.ch/svn-repos/scala/scala/trunk@17720 5e8d7ff9-d8ef-0310-90f0-a4852d11357a

build.xml

@@ -1468,13 +1468,11 @@ BOOTRAPING TEST AND TEST SUITE
 ============================================================================ -->
 
   <target name="test.stability" depends="strap.done">
-<!-- commented out for now.
+    <same dir="${build-quick.dir}" todir="${build-strap.dir}" failondifferent="no">
-    <same dir="${build-quick.dir}" todir="${build-strap.dir}" failondifferent="yes">
       <exclude name="**/*.properties"/>
       <exclude name="bin/**"/>
       <exclude name="*.complete"/>
     </same>
--->
   </target>
 
   <target name="test.run" depends="pack.done">

src/compiler/scala/tools/nsc/symtab/classfile/UnPickler.scala

@@ -68,10 +68,21 @@ abstract class UnPickler {
     private def checkVersion(filename: String) {
       val major = readNat()
       val minor = readNat()
+
+// remove the portion below, between "cut here", before releasing the first 2.8 beta
+
 //---cut here---
+
+      // transiently, use this bit as long as stability fails.
+      if (major != 4 && major != 5)
+
+      // once stability is restored, use the following bit instead:
+/*
       if (major == 4) { // !!! temporarily accept 4 as version. 
         println("WARNING: old class format, please recompile "+filename)
       } else
+*/
+
 //---cut here---
       if (major != MajorVersion || minor > MinorVersion)
         throw new IOException("Scala signature " + classRoot.name +