Fix bug in PartialPerm if length of img and dom differ

Resolve issue gap-system#2301.
ChrisJefferson · Jun 14, 2018 · 28fce77 · 28fce77
1 parent a42872a
commit 28fce77
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Showing 2 changed files with 9 additions and 2 deletions.
diff --git a/lib/pperm.gi b/lib/pperm.gi
@@ -545,12 +545,13 @@ function(arg)
     fi;
   elif Length(arg)=2 then  
     if IsSSortedList(arg[1]) and ForAll(arg[1], IsPosInt) and
-     IsDuplicateFreeList(arg[2]) and ForAll(arg[2], IsPosInt) then 
+     IsDuplicateFreeList(arg[2]) and ForAll(arg[2], IsPosInt) and
+     Length(arg[1]) = Length(arg[2]) then 
       return SparsePartialPermNC(arg[1], arg[2]); 
     else
       ErrorNoReturn("usage: the 1st argument must be a set of positive integers ",
       "and the 2nd argument must be a duplicate-free list of positive ",
-      "integers");
+      "integers of equal length to the first");
     fi;
   fi; 
 

diff --git a/tst/testinstall/pperm.tst b/tst/testinstall/pperm.tst
@@ -2440,6 +2440,12 @@ gap> MultiplicativeZeroOp(x);
 gap> MultiplicativeZero(x);
 <empty partial perm>
 
+# Test PartialPerm (for sparse incorrect arg)
+gap> PartialPerm([1,2,8],[3,4,1,2]);
+Error, usage: the 1st argument must be a set of positive integers and the 2nd \
+argument must be a duplicate-free list of positive integers of equal length to\
+ the first
+
 #
 gap> SetUserPreference("PartialPermDisplayLimit", display);;
 gap> SetUserPreference("NotationForPartialPerm", notationpp);;