diff options
| -rw-r--r-- | generic/tclCmdMZ.c | 29 | ||||
| -rw-r--r-- | tests/string.test | 6 |
2 files changed, 27 insertions, 8 deletions
diff --git a/generic/tclCmdMZ.c b/generic/tclCmdMZ.c index 30586b1..706d71c 100644 --- a/generic/tclCmdMZ.c +++ b/generic/tclCmdMZ.c @@ -2262,7 +2262,7 @@ StringRplcCmd( 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?"); @@ -2270,20 +2270,33 @@ StringRplcCmd( } ustring = Tcl_GetUnicodeFromObj(objv[1], &length); - 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)) { + /* + * The following test screens out most empty substrings as + * candidates for replacement. When they are detected, no + * replacement is done, and the result is the original string, + */ + if ((last < 0) || /* Range ends before start of string */ + (first > end) || /* Range begins after end of string */ + (last < first)) { /* Range begins after it starts */ + + /* + * BUT!!! when (end < 0) -- an empty original string -- we can + * have (first <= end < 0 <= last) and an empty string is permitted + * to be replaced. + */ Tcl_SetObjResult(interp, objv[1]); } else { Tcl_Obj *resultPtr; ustring = Tcl_GetUnicodeFromObj(objv[1], &length); - length--; + end = length-1; if (first < 0) { first = 0; @@ -2293,9 +2306,9 @@ 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); } diff --git a/tests/string.test b/tests/string.test index 39abd86..f3bb366 100644 --- a/tests/string.test +++ b/tests/string.test @@ -1294,6 +1294,12 @@ test string-14.16 {string replace} { test string-14.17 {string replace} { string replace abcdefghijklmnop end end-1 } {abcdefghijklmnop} +test string-14.18 {string replace} { + string replace abcdefghijklmnop 10 9 XXX +} {abcdefghijklmnop} +test string-14.19 {string replace} { + string replace {} -1 0 A +} A test string-15.1 {string tolower too few args} { list [catch {string tolower} msg] $msg |