Re: new module 'string-buffer'

[Bruno Haible]

This patch fixes two issues with this new module.

1) The license 'LGPLv2+' is not possible, because the dependency module
'vsnprintf' is under 'LGPL' (= 'LGPLv3+').

2) The continuous integration reported a test failure. I can reproduce it
  - on a Debian 10.7 system,
  - on an Ubuntu 16.04 system, but only when specifying CFLAGS that don't
    include optimizations. With optimizations, some fortify settings lead
    to
      gl_cv_func_printf_directive_n=no
      gl_cv_func_snprintf_directive_n=no
    and thus to
      gl_cv_func_vsnprintf_posix=no
    and so to
      REPLACE_VSNPRINTF=1 .
    The Gnulib implementation of vsnprintf() fails when an invalid format
    directive is given.
    Whereas without optimization, the glibc implementation of vsnprintf
    is POSIX compliant, hence REPLACE_VSNPRINTF=0, and since glibc vsnprintf()
    does not fail when an invalid format directive is encountered, the
    unit test failed.


2021-02-27  Bruno Haible  <bruno@clisp.org>

        string-buffer: Fixes.
        * modules/string-buffer (License): Change to LGPL.
        * tests/test-string-buffer.c (main): Add another sb_appendf call, that
        is more likely to fail.

diff --git a/modules/string-buffer b/modules/string-buffer
index 4e7827c..54da1db 100644
--- a/modules/string-buffer
+++ b/modules/string-buffer
@@ -20,7 +20,7 @@ Include:
 "string-buffer.h"
 
 License:
-LGPLv2+
+LGPL
 
 Maintainer:
 all
diff --git a/tests/test-string-buffer.c b/tests/test-string-buffer.c
index 7973559..ecf5160 100644
--- a/tests/test-string-buffer.c
+++ b/tests/test-string-buffer.c
@@ -90,12 +90,19 @@ main ()
     free (s);
   }
 
-  /* Test printf-like formatting failure.  */
+  /* Test printf-like formatting failure.
+     On all systems except AIX, trying to convert the wide-character 0x76543210
+     to a multibyte string (in the "C" locale) fails.
+     On all systems where REPLACE_VSNPRINTF=1 (this includes AIX), i.e. where
+     the Gnulib implementation of vsnprintf() is used), invalid format
+     directives make the *printf call fail.  */
   {
     struct string_buffer buffer;
 
     sb_init (&buffer);
     sb_append (&buffer, "<");
+    sb_appendf (&buffer, "%lc", 0x76543210);
+    sb_append (&buffer, "|");
     sb_appendf (&buffer, invalid_format_string_1, 1);
     sb_append (&buffer, "|");
     sb_appendf (&buffer, invalid_format_string_2, 2);