diff options
| -rw-r--r-- | generic/tclCmdMZ.c | 35 |
1 files changed, 24 insertions, 11 deletions
diff --git a/generic/tclCmdMZ.c b/generic/tclCmdMZ.c index d63a985..92f247a 100644 --- a/generic/tclCmdMZ.c +++ b/generic/tclCmdMZ.c @@ -2352,29 +2352,42 @@ StringRplcCmd( int objc, /* Number of arguments. */ Tcl_Obj *const objv[]) /* Argument objects. */ { - Tcl_UniChar *ustring; - int first, last, length; + int first, last, length, end; if (objc < 4 || objc > 5) { Tcl_WrongNumArgs(interp, 1, objv, "string first last ?string?"); return TCL_ERROR; } - ustring = Tcl_GetUnicodeFromObj(objv[1], &length); - length--; + (void) Tcl_GetUnicodeFromObj(objv[1], &length); + end = length - 1; - if (TclGetIntForIndexM(interp, objv[2], length, &first) != TCL_OK || - TclGetIntForIndexM(interp, objv[3], length, &last) != TCL_OK){ + if (TclGetIntForIndexM(interp, objv[2], end, &first) != TCL_OK || + TclGetIntForIndexM(interp, objv[3], end, &last) != TCL_OK){ return TCL_ERROR; } - if ((last < first) || (last < 0) || (first > length)) { + /* + * [string replace] does not replace empty strings. This is + * unwise, but since it is true, here we quickly screen out + * index pairs that demarcate an empty substring. + */ + + if ((last < 0) || /* Range ends before start of string */ + (first > end) || /* Range begins after end of string */ + (last < first)) { /* Range begins after it starts */ Tcl_SetObjResult(interp, objv[1]); } else { Tcl_Obj *resultPtr; - ustring = Tcl_GetUnicodeFromObj(objv[1], &length); - length--; + /* + * We are re-fetching in case the string argument is same value as + * an index argument, and shimmering cost us our ustring. + */ + + Tcl_UniChar *ustring = Tcl_GetUnicodeFromObj(objv[1], &length); + + end = length - 1; if (first < 0) { first = 0; @@ -2384,9 +2397,9 @@ StringRplcCmd( if (objc == 5) { Tcl_AppendObjToObj(resultPtr, objv[4]); } - if (last < length) { + if (last < end) { Tcl_AppendUnicodeToObj(resultPtr, ustring + last + 1, - length - last); + end - last); } Tcl_SetObjResult(interp, resultPtr); } |