diff options
| -rw-r--r-- | generic/tclCmdIL.c | 8 | ||||
| -rw-r--r-- | generic/tclStringObj.c | 2 |
2 files changed, 10 insertions, 0 deletions
diff --git a/generic/tclCmdIL.c b/generic/tclCmdIL.c index 02e5812..b303bb6 100644 --- a/generic/tclCmdIL.c +++ b/generic/tclCmdIL.c @@ -2025,6 +2025,14 @@ Tcl_JoinObjCmd( resObjPtr = Tcl_NewObj(); for (i = 0; i < listLen; i++) { if (i > 0) { + + /* + * NOTE: This code is relying on Tcl_AppendObjToObj() **NOT** + * to shimmer joinObjPtr. If it did, then the case where + * objv[1] and objv[2] are the same value would not be safe. + * Accessing elemPtrs would crash. + */ + Tcl_AppendObjToObj(resObjPtr, joinObjPtr); } Tcl_AppendObjToObj(resObjPtr, elemPtrs[i]); diff --git a/generic/tclStringObj.c b/generic/tclStringObj.c index 86f0c62..67e86c5 100644 --- a/generic/tclStringObj.c +++ b/generic/tclStringObj.c @@ -1261,6 +1261,8 @@ Tcl_AppendUnicodeToObj( * Side effects: * The string rep of appendObjPtr is appended to the string * representation of objPtr. + * IMPORTANT: This routine does not and MUST NOT shimmer appendObjPtr. + * Callers are counting on that. * *---------------------------------------------------------------------- */ |