backgroundEvalObjv - evaluate an event

static int
        BackgroundEvalObjv(Tcl_Interp *interp, 
            int objc, Tcl_Obj *const *objv, int flags)
        {
            Tcl_DString errorInfo, errorCode;
            Tcl_SavedResult state;
            int r = TCL_OK;
            
            Tcl_DStringInit(&errorInfo);
            Tcl_DStringInit(&errorCode);
            
            /*
             * Record the state of the interpreter
             */
            
            Tcl_SaveResult(interp, &state);
            Tcl_DStringAppend(&errorInfo, 
                Tcl_GetVar(interp, "errorInfo", TCL_GLOBAL_ONLY), -1);
            Tcl_DStringAppend(&errorCode, 
                Tcl_GetVar(interp, "errorCode", TCL_GLOBAL_ONLY), -1);
            
            /*
             * Evaluate the command and handle any error.
             */
            
            r = Tcl_EvalObjv(interp, objc, objv, flags);
            if (r == TCL_ERROR) {
                Tcl_AddErrorInfo(interp, "\n    (background event handler)");
                Tcl_BackgroundError(interp);
            }
            
            /*
             * Restore the state of the interpreter
             */
            
            Tcl_SetVar(interp, "errorInfo",
                Tcl_DStringValue(&errorInfo), TCL_GLOBAL_ONLY);
            Tcl_SetVar(interp, "errorCode",
                Tcl_DStringValue(&errorCode), TCL_GLOBAL_ONLY);
            Tcl_RestoreResult(interp, &state);
            
            /*
             * Clean up references.
             */
            
            Tcl_DStringFree(&errorInfo);
            Tcl_DStringFree(&errorCode);
            
            return r;
        }