bug#48578: 28.0.50; Native-compiled files of some preloaded files not loaded at dump time

[Andrea Corallo]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Andrea Corallo <akrl@sdf.org>
>> Cc: 48578@debbugs.gnu.org
>> Date: Tue, 25 May 2021 12:34:27 +0000
>> 
>> +  /* Use `file-truename' or fall back to 'realpath' `expand-file-name'
>> +     when the first is not available.  (`file-truename' is not
>> +     available only for a short phases of the bootstrap before file.el
>> +     is loaded).  */
>> +
>> +  if (NILP (Ffboundp (intern_c_string ("file-truename"))))
>> +    {
>> +#ifndef WINDOWSNT
>> +      char *file_normalized = realpath (SSDATA (filename), NULL);
>> +#else
>> +      char *file_normalized = ??? ;
>> +#endif
>> +      filename = Fexpand_file_name (build_string (file_normalized), Qnil);
>> +      xfree (file_normalized);
>> +    }
>> +  else
>> +    filename = CALL1I (file-truename, filename);
>>  
>>    if (NILP (Ffile_exists_p (filename)))
>>      xsignal1 (Qfile_missing, filename);
>
> Thanks, I will try that.  But why not use realpath at all times, even
> if file-truename is available?  They do the same thing, AFAIK, no?

AFAIK yes but the file-truename implementation didn't look sufficiently
trivial to be sure they are really equivalent with the quick skim I had.

I agree with the idea of using always one (realpath), should be also
easier to ideantify issues in case.

Attached the updated patch.

  Andrea

diff --git a/src/comp.c b/src/comp.c
index 340ed85038..e961161fc6 100644
--- a/src/comp.c
+++ b/src/comp.c
@@ -4008,15 +4008,18 @@ DEFUN ("comp-el-to-eln-rel-filename", 
Fcomp_el_to_eln_rel_filename,
 {
   CHECK_STRING (filename);
 
-  /* Use `file-truename' or fall back to `expand-file-name' when the
-     first is not available (bug#44701).
-
-     `file-truename' is not available only for a short phases of the
-     bootstrap before file.el is loaded, given we do not symlink
-     inside the build directory this should work.  */
-  filename = NILP (Ffboundp (intern_c_string ("file-truename")))
-    ? Fexpand_file_name (filename, Qnil)
-    : CALL1I (file-truename, filename);
+  /* Use `file-truename' or fall back to 'realpath' `expand-file-name'
+     when the first is not available.  (`file-truename' is not
+     available only for a short phases of the bootstrap before file.el
+     is loaded).  */
+
+#ifndef WINDOWSNT
+  char *file_normalized = realpath (SSDATA (filename), NULL);
+#else
+  char *file_normalized = ??? ;
+#endif
+  filename = Fexpand_file_name (build_string (file_normalized), Qnil);
+  xfree (file_normalized);
 
   if (NILP (Ffile_exists_p (filename)))
     xsignal1 (Qfile_missing, filename);