Merge pull request #766 from frankluebeck/fix_remove_with_holes

Fix kernel method for 'Remove' with one argument
gap-system · Apr 29, 2016 · cd4afab · cd4afab
2 parents 64f99d9 + 89dd011
commit cd4afab
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Showing 2 changed files with 21 additions and 2 deletions.
diff --git a/src/listfunc.c b/src/listfunc.c
@@ -232,8 +232,10 @@ Obj            RemPlist (
     }
     removed = ELM_PLIST(list, pos);
     SET_ELM_PLIST(list, pos, (Obj)0L);
-    SET_LEN_PLIST(list, pos-1);
-    if ( pos == 1 ) {
+    pos--;
+    while ( 1 <= pos && ELM_PLIST( list, pos ) == 0 ) { pos--; }
+    SET_LEN_PLIST(list, pos);
+    if ( pos == 0 ) {
       RetypeBag(list, T_PLIST_EMPTY);
     }
     if (4*pos*sizeof(Obj) < 3*SIZE_BAG(list))

diff --git a/tst/teststandard/bugfix.tst b/tst/teststandard/bugfix.tst
@@ -3045,6 +3045,23 @@ gap> Size(Stabilizer(g, [ [1,2], [3,4] ], OnSetsSets));
 gap> G:=Group((1,2,3,4));;Factorization(G,Elements(G)[1]);
 <identity ...>
 
+#2016/04/27 (FL, bug reported on support list)
+gap> l := [1,,,5];;
+gap> Remove(l);
+5
+gap> [l, Length(l)];
+[ [ 1 ], 1 ]
+gap> l := [,,,"x"];;
+gap> Remove(l);
+"x"
+gap> [l, Length(l)];
+[ [  ], 0 ]
+gap> l := [1,2,,[],"x"];;
+gap> Remove(l);
+"x"
+gap> [l, Length(l)];
+[ [ 1, 2,, [  ] ], 4 ]
+
 #############################################################################
 gap> STOP_TEST( "bugfix.tst", 831990000);