bug#38072: when `byte-compile-file' finds out that a file is `no-byte-compile', it ignores `load' parameter

[Stefan Kangas <stefan@marxist.se>]

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tags 38072 + patch
thanks

Paul Pogonyshev <pogonyshev@gmail.com> writes:

> After (byte-compile-file "..." t) one normally expects that the file
> is loaded, all its functions and variables are visible etc.  However,
> if file contains local variable `no-byte-compile', not only
> compilation is cancelled, `byte-compile-file' also doesn't load the
> file.
>
> Expected: if `byte-compile-file' cancels byte-compilation and `load'
> is non-nil, it should load the uncompiled source instead.

The fix is pretty simple (see attached), but I'm not sure what the
correct behavior is here.

The doc string of `byte-compile-file' says:

    Compile a file of Lisp code named FILENAME into a file of byte code.
    The output file’s name is generated by passing FILENAME to the
    function ‘byte-compile-dest-file’ (which see).
    With prefix arg (noninteractively: 2nd arg), LOAD the file after compiling.
                                                               ^^^^^^^^^^^^^^^

So should we load the file if we did not compile the file?  I'm thinking
yes, and I don't see what it could hurt to change it to load the file.
If the user uses a prefix arg or the LOAD argument from Lisp, surely
that was the intention.

But on the other hand the text above seems deliberate, somehow?  (And
AFAICT the behavior has been not to load the file since pretty much
forever, possibly since byte-compilation was first added.)

Any other opinions here?

Best regards,
Stefan Kangas

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From f48c2a446e5343f8ad104eb5523e834bb127825d Mon Sep 17 00:00:00 2001
From: Stefan Kangas <stefankangas@gmail.com>
Date: Sat, 5 Sep 2020 02:14:54 +0200
Subject: [PATCH] Ensure byte-compile-file loads file with non-nil load arg

* lisp/emacs-lisp/bytecomp.el (byte-compile-file): Load file when
argument 'load' is non-nil, even if 'no-byte-compile' is also
non-nil.  (Bug#38072)
---
 lisp/emacs-lisp/bytecomp.el | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/lisp/emacs-lisp/bytecomp.el b/lisp/emacs-lisp/bytecomp.el
index 966990bac9..d6db318e65 100644
--- a/lisp/emacs-lisp/bytecomp.el
+++ b/lisp/emacs-lisp/bytecomp.el
@@ -1970,6 +1970,9 @@ byte-compile-file
 		     (byte-compile-abbreviate-file target-file)
 		     (buffer-local-value 'no-byte-compile input-buffer))
 	    (condition-case nil (delete-file target-file) (error nil)))
+          ;; Load the file even when not byte-compiling.  (Bug#38072)
+          (when load
+            (load target-file))
 	  ;; We successfully didn't compile this file.
 	  'no-byte-compile)
       (when byte-compile-verbose
-- 
2.28.0