[Rpm-maint] [PATCH 4/5] Optimize readLine routine

[Alexey Tourbin]

On Thu, Feb 07, 2013 at 04:36:42AM +0000, Alexey Tourbin wrote:
> Update2: it is not clear whether the backslash in "\%{foo}" should
> somehow "escape" the balancing check, as it does now.  Anyway, this case
> is still subject for macro expansion.
> 
> (So I updatd the change on github, here's the relevant part:)

>  		case '\\':
>  		    switch (*(p+1)) {
> -			case '\n': p++, nc = 1; break;
> +			case '\n': p++, nc = 1; set = "\\\n%{}()"; break;
>  			case '\0': break;
> +			case '%': needExpand = 1; break;
>  			default: p++; break;

And so the change actually reinstalls balancing check in for \%{foo}.
Interestingly, there's a specfile which attempts to escape a fully
bracketed macro.

sssd.spec:
   290  for man in `find $RPM_BUILD_ROOT/%{_mandir}/??/man?/ -type f | sed -e "s#$RPM_BUILD_ROOT/%{_mandir}/##"`
   291  do
   292      lang=`echo $man | cut -c 1-2`
   293      case `basename $man` in
   294          sss_*)
   295              echo \%lang\(${lang}\) \%{_mandir}/${man}\* >> sssd_tools.lang
   296              ;;
   297          sssd_krb5_*)
   298              echo \%lang\(${lang}\) \%{_mandir}/${man}\* >> sssd_client.lang
   299              ;;
   300          pam_sss*)
   301              echo \%lang\(${lang}\) \%{_mandir}/${man}\* >> sssd_client.lang
   302              ;;
   303          sssd_krb5_locator_plugin*)
   304              echo \%lang\(${lang}\) \%{_mandir}/${man}\* >> sssd_client.lang
   305              ;;
   306          *)
   307              echo \%lang\(${lang}\) \%{_mandir}/${man}\* >> sssd.lang
   308              ;;
   309      esac
   310  done

It looks like the guy thinks that \%lang would prevent rpm from attempting
to expand %lang, much like %%lang.  In reality, the macros are expanded,
and backslashes are eaten by the shell.

$ echo \%lang \/usr/share/man
%lang /usr/share/man
$