Tcl Source Code

    if (elements == 0) {
	return Tcl_NewObj();
    }

    assert ( elements > 0 );

    for (i = 0; i < elements; i++) {
	int driveNameLength, strEltLen, length;
	Tcl_PathType type;
	char *strElt, *ptr;
	Tcl_Obj *driveName = NULL;
	Tcl_Obj *elt = objv[i];

	/*
	 * This is a special case where we can be much more efficient, where
	 * we are joining a single relative path onto an object that is
	 * already of path type. The 'TclNewFSPathObj' call below creates an
	 * object which can be normalized more efficiently. Currently we only
	 * use the special case when we have exactly two elements, but we
	 * could expand that in the future.
         *
         * Bugfix [a47641a0]. TclNewFSPathObj requires first argument
         * to be an absolute path. Added a check for that elt is absolute.
	 */

	if ((i == (elements-2)) && (i == 0)
                && (elt->typePtr == &tclFsPathType)
		&& !((elt->bytes != NULL) && (elt->bytes[0] == '\0'))
                && TclGetPathType(elt, NULL, NULL, NULL) == TCL_PATH_ABSOLUTE) {
            Tcl_Obj *tailObj = objv[i+1];


	    type = TclGetPathType(tailObj, NULL, NULL, NULL);
	    if (type == TCL_PATH_RELATIVE) {
		const char *str;
		int len;

		str = Tcl_GetStringFromObj(tailObj, &len);
		if (len == 0) {
		    /*
		     * This happens if we try to handle the root volume '/'.
		     * There's no need to return a special path object, when
		     * the base itself is just fine!
		     */

		    assert ( res == NULL );
		    return elt;
		}

		/*
		 * If it doesn't begin with '.' and is a unix path or it a
		 * windows path without backslashes, then we can be very
		 * efficient here. (In fact even a windows path with

		     * all backslashes to forward slashes, so the base part
		     * cannot have backslashes either.
		     */

		    if ((tclPlatform != TCL_PLATFORM_WINDOWS)
			    || (strchr(Tcl_GetString(elt), '\\') == NULL)) {

			assert ( res == NULL );

			if (PATHFLAGS(elt)) {
			    return TclNewFSPathObj(elt, str, len);
			}
			if (TCL_PATH_ABSOLUTE != Tcl_FSGetPathType(elt)) {
			    return TclNewFSPathObj(elt, str, len);
			}
			(void) Tcl_FSGetNormalizedPath(NULL, elt);
			if (elt == PATHOBJ(elt)->normPathPtr) {
			    return TclNewFSPathObj(elt, str, len);
			}
		    }
		}

		/*
		 * Otherwise we don't have an easy join, and we must let the
		 * more general code below handle things.
		 */
	    } else if (tclPlatform == TCL_PLATFORM_UNIX) {
		assert ( res == NULL );
		return tailObj;
	    } else {
		const char *str = TclGetString(tailObj);

		if (tclPlatform == TCL_PLATFORM_WINDOWS) {
		    if (strchr(str, '\\') == NULL) {
			assert ( res == NULL );
			return tailObj;
		    }
		}
	    }
	}











	strElt = Tcl_GetStringFromObj(elt, &strEltLen);
	driveNameLength = 0;
	type = TclGetPathType(elt, &fsPtr, &driveNameLength, &driveName);
	if (type != TCL_PATH_RELATIVE) {
	    /*
	     * Zero out the current result.
	     */