bug#30564: call-process always fails for empty exec-path

[Lars Ingebrigtsen]

Christopher Wellons <wellons@nullprogram.com> writes:

> The call-process function incorrectly fails for valid absolute paths
> when exec-path is nil:
>
>    (let ((exec-path ()))
>      (call-process "/bin/ls"))
>    ;; error: (file-error "Searching for program"
>    ;;                    "No such file or directory" "/bin/ls")
>
> Adding a single element to exec-path fixes the problem, even if that
> element is nonsense:
>
>    (let ((exec-path '(t)))
>      (call-process "/bin/ls"))
>    ;; => 0
>
> The bug is in the for loop in openp() (lread.c). The only successful
> returns are found inside the loop. An empty list results in no loop
> iterations, which means an absolute path has no chance to return
> successfully.

I've now fixed this by transforming the for loop into a do/while loop.

-- 
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   bloggy blog: http://lars.ingebrigtsen.no