Re: bug#57129: 29.0.50; Improve behavior of conditionals in Eshell

[Paul Eggert]

On 8/15/22 11:58, Eli Zaretskii wrote:

> Ah, okay.  It's a (mis)feature of Gnulib's gen_tempname function
> (which is the guts of make-temp-file) in its implementation for
> MS-Windows (and maybe other platforms?): it always begins from the
> same "random" characters in the file name, and only generates other
> random characters if there's already a file by that name.

Not sure I'd call it a misfeature, as gen_tempname is generating a 
uniquely-named file that is exclusive to Emacs, which is all it's 
supposed to do.

I do see a comment saying that gen_tempname generates "hard-to-predict" 
names, which as you note is not correct on MS-DOS, nor even strictly 
speaking on all POSIX platforms. I installed the first attached patch 
into Gnulib to fix that comment.

I'm not sure I'm entirely understanding the Emacs problem, but it 
appears to be that Emacs has its own set of filenames that it thinks it 
knows about, and Emacs wants the new temporary file's name to not be a 
member of that set. If I'm right, does the second attached patch (this 
patch is to Emacs) address the problem? I haven't tested or installed it.

0001-tempname-remove-incorrect-comment.patch
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0001-Don-t-create-temp-file-with-same-name-as-visited.patch
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