bug#40699: "dist Hook" documentation in manual is incorrect or unclear about write permissions

[Vincent Lefevre]

doc/automake.texi contains:

------------------------------------------------------------------------
@example
EXTRA_DIST = doc
dist-hook:
        rm -rf `find $(distdir)/doc -type d -name .svn`
@end example

@c The caveats described here should be documented in 'disthook.sh'.
@noindent
Note that the @code{dist-hook} recipe shouldn't assume that the regular
files in the distribution directory are writable; this might not be the
case if one is packaging from a read-only source tree, or when a
@code{make distcheck} is being done.  For similar reasons, the recipe
shouldn't assume that the subdirectories put into the distribution
directory as an effect of having them listed in @code{EXTRA_DIST} are
writable.  So, if the @code{dist-hook} recipe wants to modify the
content of an existing file (or @code{EXTRA_DIST} subdirectory) in the
distribution directory, it should explicitly to make it writable first:

@example
EXTRA_DIST = README doc
dist-hook:
        chmod u+w $(distdir)/README $(distdir)/doc
        echo "Distribution date: `date`" >> README
        rm -f $(distdir)/doc/HACKING
@end example
------------------------------------------------------------------------

So, if the subdirectories may not be writable, how can the rm in the
first example work without changing the permissions first?

-- 
Vincent Lefèvre <address@hidden> - Web: <https://www.vinc17.net/>
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Work: CR INRIA - computer arithmetic / AriC project (LIP, ENS-Lyon)