[FYI] {maint} texi: warn against suffix-less input files

[Stefano Lattarini]

The warning being in the 'obsolete' category.  This is mostly to
ease transition to Automake-NG (see commit v1.12.1-392-ga0c7b6a),
and to discourage use of seldom-tested setups.

* automake.in (scan_texinfo_file): Warn against '@setfilename'
directives that specify suffix-less output info files.
* t/txinfo-without-info-suffix.sh: Adjust and enhance.
* t/txinfo-makeinfo-error-no-clobber.sh: No longer use suffix-less
info files in '@setfilename' directives.
* t/primary-prefix-valid-couples.sh: Likewise.
* t/txinfo-setfilename-repeated.sh: Likewise.
* t/txinfo-vtexi2.sh : Likewise.
* t/mdate2.sh: Likewise.
* NEWS: Update.

Signed-off-by: Stefano Lattarini <address@hidden>
---
 NEWS                                  |  6 ++++++
 automake.in                           |  9 ++++++---
 t/mdate2.sh                           |  2 +-
 t/primary-prefix-valid-couples.sh     |  2 +-
 t/txinfo-makeinfo-error-no-clobber.sh | 20 ++++++++++----------
 t/txinfo-setfilename-repeated.sh      |  6 ++++--
 t/txinfo-vtexi2.sh                    |  2 +-
 t/txinfo-without-info-suffix.sh       |  6 +++++-
 8 files changed, 34 insertions(+), 19 deletions(-)

diff --git a/NEWS b/NEWS
index c5b6514..0e5455b 100644
--- a/NEWS
+++ b/NEWS
@@ -49,6 +49,12 @@ New in 1.13.2:
     should take precedence over the same-named automake-provided macro
     (defined in '/usr/local/share/aclocal-1.14/vala.m4').
 
+* Obsolescent features:
+
+  - Use of suffix-less info files (that can be specified through the
+    '@setfilename' macro in Texinfo input files) is discouraged, and
+    its use will raise warnings in the 'obsolete' category.
+
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 New in 1.13.1:
diff --git a/automake.in b/automake.in
index 0764258..2f60c18 100644
--- a/automake.in
+++ b/automake.in
@@ -2993,9 +2993,12 @@ sub scan_texinfo_file ($)
          next if $outfile;
 
          $outfile = $1;
-         # TODO: In Automake 1.14 (or even 1.13.2), start warning against
-         # TODO: suffixes != ".info", to ease transition to Automake-NG.
-         if ($outfile =~ /\.([^.]+)$/ && $1 ne 'info')
+         if (index ($outfile, '.') < 0)
+           {
+             msg 'obsolete', "$filename:$.",
+                 "use of suffix-less info files is discouraged"
+           }
+         elsif ($outfile !~ /\.info$/)
            {
              error ("$filename:$.",
                     "output '$outfile' has unrecognized extension");
diff --git a/t/mdate2.sh b/t/mdate2.sh
index 79e414b..fa41864 100755
--- a/t/mdate2.sh
+++ b/t/mdate2.sh
@@ -29,7 +29,7 @@ END
 # Required when using Texinfo.
 : > texinfo.tex
 : > mdate-sh
-echo '@setfilename textutils' > textutils.texi
+echo '@setfilename textutils.info' > textutils.texi
 
 # Use "././" to confuse Automake into thinking this is a subdir build.
 $ACLOCAL
diff --git a/t/primary-prefix-valid-couples.sh 
b/t/primary-prefix-valid-couples.sh
index 502967f..17a2a9b 100755
--- a/t/primary-prefix-valid-couples.sh
+++ b/t/primary-prefix-valid-couples.sh
@@ -38,7 +38,7 @@ AC_DEFUN([AC_PROG_LIBTOOL],
 END
 
 # Other required files.
-echo '@setfilename foo' > foo.texi
+echo '@setfilename foo.info' > foo.texi
 : > texinfo.tex
 : > py-compile
 : > ar-lib
diff --git a/t/txinfo-makeinfo-error-no-clobber.sh 
b/t/txinfo-makeinfo-error-no-clobber.sh
index cddbc13..f4b7d01 100755
--- a/t/txinfo-makeinfo-error-no-clobber.sh
+++ b/t/txinfo-makeinfo-error-no-clobber.sh
@@ -29,7 +29,7 @@ mkdir sub
 
 cat > main.texi << 'END'
 \input texinfo
address@hidden main
address@hidden main.info
 @settitle main
 @node Top
 Hello walls.
@@ -46,15 +46,15 @@ $AUTOCONF
 $MAKE
 
 # Feign more info files.
-: > main-1
-: > sub/main-1
+: > main.info-1
+: > sub/main.info-1
 
 # Break main.texi.
 $sleep
 cp main.texi main.old
 cat > main.texi << 'END'
 \input texinfo
address@hidden main
address@hidden main.info
 @settitle main
 @node Top
 @unknown_macro{Hello walls.}
@@ -63,16 +63,16 @@ END
 
 # makeinfo will bail out, but we should conserve the old info files.
 $MAKE && exit 1
-test -f main
-test -f main-1
+test -f main.info
+test -f main.info-1
 
 # Restore main.texi, and break sub/main.texi.
 cp main.texi sub/main.texi
 mv main.old main.texi
 $MAKE && exit 1
-test -f main
-test ! -e main-1
-test -f sub/main
-test -f sub/main-1
+test -f main.info
+test ! -e main.info-1
+test -f sub/main.info
+test -f sub/main.info-1
 
 :
diff --git a/t/txinfo-setfilename-repeated.sh b/t/txinfo-setfilename-repeated.sh
index 1731dff..d06b9b9 100755
--- a/t/txinfo-setfilename-repeated.sh
+++ b/t/txinfo-setfilename-repeated.sh
@@ -24,7 +24,7 @@ info_TEXINFOS = texinfo.texi
 END
 
 cat > texinfo.texi << 'END'
address@hidden texinfo
address@hidden texinfo.info
 ...
 @verbatim
 @setfilename example.info
@@ -36,4 +36,6 @@ $ACLOCAL
 $AUTOMAKE --add-missing
 
 grep 'example' Makefile.in && exit 1
-grep 'texinfo:' Makefile.in
+grep 'texinfo\.info:' Makefile.in
+
+:
diff --git a/t/txinfo-vtexi2.sh b/t/txinfo-vtexi2.sh
index 0d12cc3..72bad5d 100755
--- a/t/txinfo-vtexi2.sh
+++ b/t/txinfo-vtexi2.sh
@@ -26,7 +26,7 @@ info_TEXINFOS = zardoz.texi
 END
 
 cat > zardoz.texi << 'END'
address@hidden zardoz
address@hidden zardoz.info
 @include version.texi
 END
 
diff --git a/t/txinfo-without-info-suffix.sh b/t/txinfo-without-info-suffix.sh
index b87ceb8..29bfbc9 100755
--- a/t/txinfo-without-info-suffix.sh
+++ b/t/txinfo-without-info-suffix.sh
@@ -29,6 +29,7 @@ END
 
 cat > textutils.texi <<EOF
 \input texinfo
address@hidden dummy comment
 @setfilename textutils
 @settitle main
 @node Top
@@ -38,7 +39,10 @@ EOF
 
 $ACLOCAL
 $AUTOCONF
-$AUTOMAKE --add-missing
+AUTOMAKE_fails -a
+$EGREP '^(\./)?textutils\.texi:3:.*suffix-less info file' stderr
+
+$AUTOMAKE -a -Wno-obsolete
 
 grep '^INFO_DEPS.*textutils$' Makefile.in
 
-- 
1.8.1.rc3.27.g3b73c7d