Inpired by [pyk-emptystring] branch: Shortcuts/speedsup in number handling when dicts or lists are involved. Suppress generation of string rep in more situations.

1 files changed, 3 insertions, 1 deletions

diff --git a/generic/tclListObj.c b/generic/tclListObj.c
index c9fd333..749f5f2 100644
--- a/generic/tclListObj.c
+++ b/generic/tclListObj.c
@@ -415,7 +415,9 @@ TclListObjCopy(
     }
 
     TclNewObj(copyPtr);
-    TclInvalidateStringRep(copyPtr);
+    if (ListRepPtr(listPtr)->elemCount > 0) {
+	TclInvalidateStringRep(copyPtr);
+    }
     DupListInternalRep(listPtr, copyPtr);
     return copyPtr;
 }