Hmm, pity that I did not check the safe.test, but seeing @dgp amend [b756080dc6f8cd05], the whole fix looks a bit weird to me now, because there is no line 59 in code of interp eval (basically the evaluating scripts are single-line scripts).

If I do debug-logging from Tcl_TransferResult, it does that 3 times during test safe-10.4.1, for instance:

```
******** 04128CA8 ==> 014058B0 : 1 - can't use package in a safe interpreter: no Safepkg1_SafeInit procedure
    while executing
"load {} Safepkg1 x"
******** 014058B0 ==> 04128CA8 : 59 - load of binary library for package Safepkg1 failed: can't use package in a safe interpreter: no Safepkg1_SafeInit procedure
******** 04128CA8 ==> 014058B0 : 1 - load of binary library for package Safepkg1 failed: can't use package in a safe interpreter: no Safepkg1_SafeInit procedure
    ("interp eval" body line 59)
    invoked from within
"load {} Safepkg1 x"
```
(where only middle has errorLine = 59, probably some old value that did not reset in-between)...

Anyway, this doesn't look correct to me. I'll fix it soon.