[Nice-commit] Nice/src/mlsub/typing/lowlevel K0.java,1.19,1.20

[<bo...@us...>]

Update of /cvsroot/nice/Nice/src/mlsub/typing/lowlevel
In directory sc8-pr-cvs1:/tmp/cvs-serv16116/src/mlsub/typing/lowlevel

Modified Files:
	K0.java 
Log Message:
Handle backup when some lowlevel constraint has been created on the fly
at a point where (several) backups existed.


Index: K0.java
===================================================================
RCS file: /cvsroot/nice/Nice/src/mlsub/typing/lowlevel/K0.java,v
retrieving revision 1.19
retrieving revision 1.20
diff -C2 -d -r1.19 -r1.20
*** K0.java	26 Jun 2003 10:37:13 -0000	1.19
--- K0.java	11 Sep 2003 20:01:03 -0000	1.20
***************
*** 1372,1377 ****
    // backtrack to the situation the last time mark() has been called
    public void backtrack() {
      S.assume(S.a&& hasBeenInitialized);
-     S.assume(S.a&& backup != null, "backtrack() without corresponding mark()");
  
      this.m = backup.savedM;
--- 1372,1381 ----
    // backtrack to the situation the last time mark() has been called
    public void backtrack() {
+     if (backup == null)
+       // This can happen for a K0 that has been created on the fly
+       // at a point where (several) backups existed.
+       return;
+ 
      S.assume(S.a&& hasBeenInitialized);
  
      this.m = backup.savedM;