Fix PermList for descending ranges

gap-system · May 4, 2020 · 7b14c09 · 7b14c09
1 parent edc5339
commit 7b14c09
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Showing 2 changed files with 4 additions and 2 deletions.
diff --git a/src/permutat.cc b/src/permutat.cc
@@ -1080,8 +1080,6 @@ static Obj FuncPermList(Obj self, Obj list)
         if (IS_RANGE(list)) {
             if (GET_LOW_RANGE(list) == 1 && GET_INC_RANGE(list) == 1)
                 return IdentityPerm;
-            else
-                return Fail;
         }
         list = PLAIN_LIST_COPY(list);
     }

diff --git a/tst/testinstall/perm.tst b/tst/testinstall/perm.tst
@@ -301,6 +301,10 @@ gap> ForAll(checklens, n -> not(
 >  PermList(Concatenation([1..n-1], [n+1,n,n+2,n+4,n+3])) =
 >  PermList(Concatenation([1..n-1], [n+1,n+2,n,n+4,n+3]))));
 true
+gap> PermList([1..5]);
+()
+gap> PermList([5,4..1]);
+(1,5)(2,4)
 
 # PermList error handling
 gap> PermList(1);