diff options
Diffstat (limited to 'generic/tclListObj.c')
| -rw-r--r-- | generic/tclListObj.c | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/generic/tclListObj.c b/generic/tclListObj.c index 975bc2e..36914bc 100644 --- a/generic/tclListObj.c +++ b/generic/tclListObj.c @@ -1616,8 +1616,8 @@ TclListObjRange( * TclListObjGetElement -- * * Returns a single element from the array of the elements in a list - * object, without doing doing any bounds checking. Caller must ensure - * that ObjPtr of of type 'tclListType' and that index is valid for the + * object, without doing any bounds checking. Caller must ensure + * that ObjPtr of type 'tclListType' and that index is valid for the * list. * *---------------------------------------------------------------------- @@ -1776,6 +1776,16 @@ Tcl_ListObjAppendList( } if (elemCount <= 0) { + /* + * Note that when elemCount <= 0, this routine is logically a + * no-op, removing and adding no elements to the list. However, by removing + * the string representation, we get the important side effect that the + * resulting listPtr is a list in canonical form. This is important. + * Resist any temptation to optimize this case further. See bug [e38dce74e2]. + */ + if (!ListObjIsCanonical(toObj)) { + TclInvalidateStringRep(toObj); + } /* Nothing to do. Note AFTER check for list above */ return TCL_OK; } |