Re: AT_BANNER() with empty argument

[Ralf Wildenhues]

* Ralf Wildenhues wrote on Sat, Jul 31, 2010 at 06:31:54PM CEST:
> Quick question: we document
> 
>  -- Macro: AT_BANNER (TEST-CATEGORY-NAME)
>      This macro identifies the start of a category of related test
>      groups.  When the resulting `testsuite' is invoked with more than
>      one test group to run, its output will include a banner containing
>      TEST-CATEGORY-NAME prior to any tests run from that category.  The
>      banner should be no more than about 40 or 50 characters.  A blank
>      banner will not print, effectively ending a category and letting
>      subsequent test groups behave as though they are uncategorized
>      when run in isolation.
> 
> but empty argument to AT_BANNER will not cause separation line from
> previous category with current code, making it look as though the coming
> test groups belong to the previous category.  Do you agree that we
> should fix the code rather than the documentation?
> (See 'Banners' test for an example of this.)

Patch to do what I meant.  Look at the output of this:
  make check TESTSUITEFLAGS='-v -d -x -k banners'

rather than my confused post above, and sorry about the description, I
failed to understand the manual correctly; hope my patch clears that up.

A single space should be unlikely enough to not be passed by users.

Also, looking back at
<http://lists.gnu.org/archive/html/autoconf-patches/2007-10/msg00186.html>
it seems I made you introduce that slight misfeature for optimization
purposes, so sorry about that.  ;-)

Thanks,
Ralf

    Ensure unnamed test group categories are separated from previous.
    
    * doc/autoconf.texi (Writing Testsuites) <AT_BANNER>: Update
    description.
    * lib/autotest/general.m4 (AT_INIT) <at_fn_banner>: Set banner
    to single space, not empty line, once printed.  For empty
    banners, print a single empty line to separate them from a
    previous test group category.
    * tests/autotest.at (Banners): Insert another test group; adjust
    tests accordingly.  Extend test to cover semantic change.
    * NEWS: Update.

diff --git a/NEWS b/NEWS
index b59716c..909e9d6 100644
--- a/NEWS
+++ b/NEWS
@@ -3,6 +3,9 @@ GNU Autoconf NEWS - User visible changes.
 * Noteworthy changes in release ?.? (????-??-??) [?]
 
 
+** AT_BANNER() with empty argument will cause visual separation from previous
+   test cagegory.
+
 * Major changes in Autoconf 2.67 (2010-07-21) [stable]
   Released by Eric Blake, based on git versions 2.66.*.
 
diff --git a/doc/autoconf.texi b/doc/autoconf.texi
index 7e804a7..df0e298 100644
--- a/doc/autoconf.texi
+++ b/doc/autoconf.texi
@@ -23755,9 +23755,8 @@ Writing Testsuites
 group to run, its output will include a banner containing
 @var{test-category-name} prior to any tests run from that category.  The
 banner should be no more than about 40 or 50 characters.  A blank banner
-will not print, effectively ending a category and letting subsequent
-test groups behave as though they are uncategorized when run in
-isolation.
+indicates uncategorized tests; an empty line will be inserted after
+tests from an earlier category, effectively ending that category.
 @end defmac
 
 @defmac AT_SETUP (@var{test-group-name})
diff --git a/lib/autotest/general.m4 b/lib/autotest/general.m4
index ba576e3..170200c 100644
--- a/lib/autotest/general.m4
+++ b/lib/autotest/general.m4
@@ -233,7 +233,7 @@ case $at_groups in
       at_print_banners=: ;;
   * ) at_print_banners=false ;;
 esac
-# Text for banner N, set to empty once printed.
+# Text for banner N, set to a single space once printed.
 m4_divert_pop([BANNERS])dnl back to DEFAULTS
 m4_divert_push([PREPARE_TESTS])dnl
 
@@ -246,9 +246,13 @@ at_fn_banner ()
 {
   $at_print_banners || return 0
   eval at_banner_text=\$at_banner_text_$[1]
-  test "x$at_banner_text" = x && return 0
-  eval at_banner_text_$[1]=
-  AS_ECHO(["$as_nl$at_banner_text$as_nl"])
+  test "x$at_banner_text" = "x " && return 0
+  eval "at_banner_text_$[1]=\" \""
+  if test -z "$at_banner_text"; then
+    $at_first || echo
+  else
+    AS_ECHO(["$as_nl$at_banner_text$as_nl"])
+  fi
 } # at_fn_banner
 
 AS_FUNCTION_DESCRIBE([at_fn_check_prepare_notrace], [REASON LINE],
diff --git a/tests/autotest.at b/tests/autotest.at
index fd3787a..c03c126 100644
--- a/tests/autotest.at
+++ b/tests/autotest.at
@@ -956,15 +956,18 @@ AT_CHECK(:)
 AT_CLEANUP
 
 AT_BANNER()
-AT_SETUP(two)# 4
+AT_SETUP(two a)# 4
+AT_CHECK(:)
+AT_CLEANUP
+AT_SETUP(two b)# 5
 AT_CHECK(:)
 AT_CLEANUP
 
 AT_BANNER([second])
-AT_SETUP(three a)# 5
+AT_SETUP(three a)# 6
 AT_CHECK(:)
 AT_CLEANUP
-AT_SETUP(three b)# 6
+AT_SETUP(three b)# 7
 AT_CHECK(:)
 AT_CLEANUP
 ]])
@@ -983,8 +986,11 @@ AT_CHECK_BANNERS([-2],             [first], [1], [second], 
[0])
 AT_CHECK_BANNERS([-3],         [first], [1], [second], [0])
 AT_CHECK_BANNERS([-k one],     [first], [1], [second], [0])
 AT_CHECK_BANNERS([3-4],                [first], [1], [second], [0])
-AT_CHECK_BANNERS([3-5],                [first], [1], [second], [1])
-AT_CHECK_BANNERS([4-5],                [first], [0], [second], [1])
+dnl There should be an empty line separating the first category from the
+dnl unnamed one.
+AT_CHECK([sed -n '/one b/,/two a/p' stdout | grep '^$'], [0], [ignore])
+AT_CHECK_BANNERS([3-6],                [first], [1], [second], [1])
+AT_CHECK_BANNERS([4-6],                [first], [0], [second], [1])
 AT_CHECK_BANNERS([3-],         [first], [1], [second], [1])
 AT_CHECK_BANNERS([-k a],       [first], [1], [second], [1])
 AT_CHECK_BANNERS([4],          [first], [0], [second], [0])