diff options
Diffstat (limited to 'generic/tclObj.c')
| -rw-r--r-- | generic/tclObj.c | 19 |
1 files changed, 18 insertions, 1 deletions
diff --git a/generic/tclObj.c b/generic/tclObj.c index 72de8f4..56d42a6 100644 --- a/generic/tclObj.c +++ b/generic/tclObj.c @@ -13,7 +13,7 @@ * See the file "license.terms" for information on usage and redistribution of * this file, and for a DISCLAIMER OF ALL WARRANTIES. * - * RCS: @(#) $Id: tclObj.c,v 1.149 2009/02/03 18:16:07 dkf Exp $ + * RCS: @(#) $Id: tclObj.c,v 1.150 2009/02/10 17:09:09 dgp Exp $ */ #include "tclInt.h" @@ -1068,11 +1068,28 @@ Tcl_GetString( return objPtr->bytes; } + /* + * Note we do not check for objPtr->typePtr == NULL. An invariant of + * a properly maintained Tcl_Obj is that at least one of objPtr->bytes + * and objPtr->typePtr must not be NULL. If broken extensions fail to + * maintain that invariant, we can crash here. + */ + if (objPtr->typePtr->updateStringProc == NULL) { + /* + * Those Tcl_ObjTypes which choose not to define an updateStringProc + * must be written in such a way that (objPtr->bytes) never becomes + * NULL. This panic was added in Tcl 8.1. + */ Tcl_Panic("UpdateStringProc should not be invoked for type %s", objPtr->typePtr->name); } objPtr->typePtr->updateStringProc(objPtr); + if (objPtr->bytes == NULL || objPtr->length < 0 + || objPtr->bytes[objPtr->length] != '\0') { + Tcl_Panic("UpdateStringProc for type '%s' " + "failed to create a valid string rep", objPtr->typePtr->name); + } return objPtr->bytes; } |