Update.

11 files changed, 387 insertions, 58 deletions

diff --git a/gl/gai_strerror.c b/gl/gai_strerror.c
index 7f0e034e66..aa733d6cc3 100644
--- a/gl/gai_strerror.c
+++ b/gl/gai_strerror.c
@@ -52,6 +52,7 @@ values[] =
     { EAI_SERVICE, N_("Servname not supported for ai_socktype") },
     { EAI_SOCKTYPE, N_("ai_socktype not supported") },
     { EAI_SYSTEM, N_("System error") },
+    { EAI_OVERFLOW, N_("Argument buffer too small") },
 #ifdef __USE_GNU
     { EAI_INPROGRESS, N_("Processing request in progress") },
     { EAI_CANCELED, N_("Request canceled") },
diff --git a/gl/gnulib.mk b/gl/gnulib.mk
index 85c3104bdc..a1e584fb53 100644
--- a/gl/gnulib.mk
+++ b/gl/gnulib.mk
@@ -29,7 +29,7 @@ BUILT_SOURCES += $(ARPA_INET_H)
 # We need the following in order to create <arpa/inet.h> when the system
 # doesn't have one.
 arpa/inet.h:
-	test -d arpa || mkdir arpa
+	@MKDIR_P@ arpa
 	rm -f $@-t $@
 	{ echo '/* DO NOT EDIT! GENERATED AUTOMATICALLY! */'; \
 	  echo '#include <sys/socket.h>'; \
@@ -107,7 +107,7 @@ BUILT_SOURCES += $(NETINET_IN_H)
 # We need the following in order to create <netinet/in.h> when the system
 # doesn't have one.
 netinet/in.h:
-	test -d netinet || mkdir netinet
+	@MKDIR_P@ netinet
 	rm -f $@-t $@
 	{ echo '/* DO NOT EDIT! GENERATED AUTOMATICALLY! */'; \
 	  echo '#include <sys/socket.h>'; \
@@ -164,6 +164,21 @@ string.h: string_.h
 	rm -f $@-t $@
 	{ echo '/* DO NOT EDIT! GENERATED AUTOMATICALLY! */' && \
 	  sed -e 's|@''ABSOLUTE_STRING_H''@|$(ABSOLUTE_STRING_H)|g' \
+	      -e 's|@''GNULIB_MEMMEM''@|$(GNULIB_MEMMEM)|g' \
+	      -e 's|@''GNULIB_MEMPCPY''@|$(GNULIB_MEMPCPY)|g' \
+	      -e 's|@''GNULIB_MEMRCHR''@|$(GNULIB_MEMRCHR)|g' \
+	      -e 's|@''GNULIB_STPCPY''@|$(GNULIB_STPCPY)|g' \
+	      -e 's|@''GNULIB_STPNCPY''@|$(GNULIB_STPNCPY)|g' \
+	      -e 's|@''GNULIB_STRCASE''@|$(GNULIB_STRCASE)|g' \
+	      -e 's|@''GNULIB_STRCHRNUL''@|$(GNULIB_STRCHRNUL)|g' \
+	      -e 's|@''GNULIB_STRDUP''@|$(GNULIB_STRDUP)|g' \
+	      -e 's|@''GNULIB_STRNDUP''@|$(GNULIB_STRNDUP)|g' \
+	      -e 's|@''GNULIB_STRNLEN''@|$(GNULIB_STRNLEN)|g' \
+	      -e 's|@''GNULIB_STRPBRK''@|$(GNULIB_STRPBRK)|g' \
+	      -e 's|@''GNULIB_STRSEP''@|$(GNULIB_STRSEP)|g' \
+	      -e 's|@''GNULIB_STRSTR''@|$(GNULIB_STRSTR)|g' \
+	      -e 's|@''GNULIB_STRCASESTR''@|$(GNULIB_STRCASESTR)|g' \
+	      -e 's|@''GNULIB_STRTOK_R''@|$(GNULIB_STRTOK_R)|g' \
 	      -e 's|@''HAVE_DECL_MEMMEM''@|$(HAVE_DECL_MEMMEM)|g' \
 	      -e 's|@''HAVE_MEMPCPY''@|$(HAVE_MEMPCPY)|g' \
 	      -e 's|@''HAVE_DECL_MEMRCHR''@|$(HAVE_DECL_MEMRCHR)|g' \
diff --git a/gl/m4/gnulib-comp.m4 b/gl/m4/gnulib-comp.m4
index e2bf48a432..356948cf01 100644
--- a/gl/m4/gnulib-comp.m4
+++ b/gl/m4/gnulib-comp.m4
@@ -41,6 +41,7 @@ AC_DEFUN([gl_INIT],
   gl_cond_libtool=true
   gl_source_base='gl'
   gl_HEADER_ARPA_INET
+  AC_PROG_MKDIR_P
   dnl gl_USE_SYSTEM_EXTENSIONS must be added quite early to configure.ac.
   gl_GETADDRINFO
   gl_FUNC_GETDELIM
@@ -49,10 +50,12 @@ AC_DEFUN([gl_INIT],
   gl_INET_NTOP
   gl_INET_PTON
   gl_HEADER_NETINET_IN
+  AC_PROG_MKDIR_P
   gl_FUNC_READLINE
   gl_TYPE_SOCKLEN_T
   AM_STDBOOL_H
   gl_FUNC_STRDUP
+  gl_STRING_MODULE_INDICATOR([strdup])
   gl_HEADER_STRING_H
   gl_HEADER_SYS_SOCKET
   AC_PROG_MKDIR_P
diff --git a/gl/m4/socklen.m4 b/gl/m4/socklen.m4
index 5e3765a64b..e824a09f56 100644
--- a/gl/m4/socklen.m4
+++ b/gl/m4/socklen.m4
@@ -1,5 +1,5 @@
-# socklen.m4 serial 4
-dnl Copyright (C) 2005, 2006 Free Software Foundation, Inc.
+# socklen.m4 serial 5
+dnl Copyright (C) 2005, 2006, 2007 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
 dnl with or without modifications, as long as this notice is preserved.
@@ -19,7 +19,7 @@ AC_DEFUN([gl_TYPE_SOCKLEN_T],
   [AC_REQUIRE([gl_HEADER_SYS_SOCKET])dnl
    AC_CHECK_TYPE([socklen_t], ,
      [AC_MSG_CHECKING([for socklen_t equivalent])
-      AC_CACHE_VAL([gl_cv_gl_cv_socklen_t_equiv],
+      AC_CACHE_VAL([gl_cv_socklen_t_equiv],
 	[# Systems have either "struct sockaddr *" or
 	 # "void *" as the second argument to getpeername
 	 gl_cv_socklen_t_equiv=
diff --git a/gl/m4/string_h.m4 b/gl/m4/string_h.m4
index 84db7a59ba..8e0be44f85 100644
--- a/gl/m4/string_h.m4
+++ b/gl/m4/string_h.m4
@@ -18,6 +18,7 @@ AC_DEFUN([gl_HEADER_STRING_H_BODY],
 [
   AC_REQUIRE([AC_C_RESTRICT])
   AC_REQUIRE([gl_HEADER_STRING_H_DEFAULTS])
+  AC_REQUIRE([gl_STRING_MODULE_INDICATOR_DEFAULTS])
   gl_ABSOLUTE_HEADER([string.h])
   ABSOLUTE_STRING_H=\"$gl_cv_absolute_string_h\"
   AC_SUBST([ABSOLUTE_STRING_H])
@@ -44,3 +45,29 @@ AC_DEFUN([gl_HEADER_STRING_H_DEFAULTS],
   REPLACE_STRSTR=0;		AC_SUBST([REPLACE_STRSTR])
   REPLACE_STRCASESTR=0;		AC_SUBST([REPLACE_STRCASESTR])
 ])
+
+AC_DEFUN([gl_STRING_MODULE_INDICATOR],
+[
+  dnl Use AC_REQUIRE here, so that the default settings are expanded once only.
+  AC_REQUIRE([gl_STRING_MODULE_INDICATOR_DEFAULTS])
+  GNULIB_[]m4_translit([$1],[abcdefghijklmnopqrstuvwxyz./-],[ABCDEFGHIJKLMNOPQRSTUVWXYZ___])=1
+])
+
+AC_DEFUN([gl_STRING_MODULE_INDICATOR_DEFAULTS],
+[
+  GNULIB_MEMMEM=0;      AC_SUBST([GNULIB_MEMMEM])
+  GNULIB_MEMPCPY=0;     AC_SUBST([GNULIB_MEMPCPY])
+  GNULIB_MEMRCHR=0;     AC_SUBST([GNULIB_MEMRCHR])
+  GNULIB_STPCPY=0;      AC_SUBST([GNULIB_STPCPY])
+  GNULIB_STPNCPY=0;     AC_SUBST([GNULIB_STPNCPY])
+  GNULIB_STRCASE=0;     AC_SUBST([GNULIB_STRCASE])
+  GNULIB_STRCHRNUL=0;   AC_SUBST([GNULIB_STRCHRNUL])
+  GNULIB_STRDUP=0;      AC_SUBST([GNULIB_STRDUP])
+  GNULIB_STRNDUP=0;     AC_SUBST([GNULIB_STRNDUP])
+  GNULIB_STRNLEN=0;     AC_SUBST([GNULIB_STRNLEN])
+  GNULIB_STRPBRK=0;     AC_SUBST([GNULIB_STRPBRK])
+  GNULIB_STRSEP=0;      AC_SUBST([GNULIB_STRSEP])
+  GNULIB_STRSTR=0;      AC_SUBST([GNULIB_STRSTR])
+  GNULIB_STRCASESTR=0;  AC_SUBST([GNULIB_STRCASESTR])
+  GNULIB_STRTOK_R=0;    AC_SUBST([GNULIB_STRTOK_R])
+])
diff --git a/gl/string_.h b/gl/string_.h
index 94d991cf06..3947241815 100644
--- a/gl/string_.h
+++ b/gl/string_.h
@@ -21,39 +21,95 @@
 
 #include @ABSOLUTE_STRING_H@
 
+
+/* GL_LINK_WARNING("literal string") arranges to emit the literal string as
+   a linker warning on most glibc systems.
+   We use a linker warning rather than a preprocessor warning, because
+   #warning cannot be used inside macros.  */
+#ifndef GL_LINK_WARNING
+  /* This works on platforms with GNU ld and ELF object format.
+     Testing __GLIBC__ is sufficient for asserting that GNU ld is in use.
+     Testing __ELF__ guarantees the ELF object format.
+     Testing __GNUC__ is necessary for the compound expression syntax.  */
+# if defined __GLIBC__ && defined __ELF__ && defined __GNUC__
+#  define GL_LINK_WARNING(message) \
+     GL_LINK_WARNING1 (__FILE__, __LINE__, message)
+#  define GL_LINK_WARNING1(file, line, message) \
+     GL_LINK_WARNING2 (file, line, message)  /* macroexpand file and line */
+#  define GL_LINK_WARNING2(file, line, message) \
+     GL_LINK_WARNING3 (file ":" #line ": " message)
+#  define GL_LINK_WARNING3(message) \
+     ({ static const char warning[sizeof (message)]		\
+          __attribute__ ((__unused__,				\
+                          __section__ (".gnu.warning"),		\
+                          __aligned__ (1)))			\
+          = message "\n";					\
+        (void)0;						\
+     })
+# else
+#  define GL_LINK_WARNING(message) ((void) 0)
+# endif
+#endif
+
+
 #ifdef __cplusplus
 extern "C" {
 #endif
 
 /* Return the first occurrence of NEEDLE in HAYSTACK.  */
-#if ! @HAVE_DECL_MEMMEM@
+#if @GNULIB_MEMMEM@
+# if ! @HAVE_DECL_MEMMEM@
 extern void *memmem (void const *__haystack, size_t __haystack_len,
 		     void const *__needle, size_t __needle_len);
+# endif
+#elif defined GNULIB_POSIXCHECK
+# undef memmem
+# define memmem memmem_is_unportable__use_gnulib_module_memmem_for_portability
 #endif
 
 /* Copy N bytes of SRC to DEST, return pointer to bytes after the
    last written byte.  */
-#if ! @HAVE_MEMPCPY@
+#if @GNULIB_MEMPCPY@
+# if ! @HAVE_MEMPCPY@
 extern void *mempcpy (void *restrict __dest, void const *restrict __src,
 		      size_t __n);
+# endif
+#elif defined GNULIB_POSIXCHECK
+# undef mempcpy
+# define mempcpy mempcpy_is_unportable__use_gnulib_module_mempcpy_for_portability
 #endif
 
 /* Search backwards through a block for a byte (specified as an int).  */
-#if ! @HAVE_DECL_MEMRCHR@
+#if @GNULIB_MEMRCHR@
+# if ! @HAVE_DECL_MEMRCHR@
 extern void *memrchr (void const *, int, size_t);
+# endif
+#elif defined GNULIB_POSIXCHECK
+# undef memrchr
+# define memrchr memrchr_is_unportable__use_gnulib_module_memrchr_for_portability
 #endif
 
 /* Copy SRC to DST, returning the address of the terminating '\0' in DST.  */
-#if ! @HAVE_STPCPY@
+#if @GNULIB_STPCPY@
+# if ! @HAVE_STPCPY@
 extern char *stpcpy (char *restrict __dst, char const *restrict __src);
+# endif
+#elif defined GNULIB_POSIXCHECK
+# undef stpcpy
+# define stpcpy stpcpy_is_unportable__use_gnulib_module_stpcpy_for_portability
 #endif
 
 /* Copy no more than N bytes of SRC to DST, returning a pointer past the
    last non-NUL byte written into DST.  */
-#if ! @HAVE_STPNCPY@
-# define stpncpy gnu_stpncpy
+#if @GNULIB_STPNCPY@
+# if ! @HAVE_STPNCPY@
+#  define stpncpy gnu_stpncpy
 extern char *stpncpy (char *restrict __dst, char const *restrict __src,
 		      size_t __n);
+# endif
+#elif defined GNULIB_POSIXCHECK
+# undef stpncpy
+# define stpncpy stpncpy_is_unportable__use_gnulib_module_stpncpy_for_portability
 #endif
 
 /* Compare strings S1 and S2, ignoring case, returning less than, equal to or
@@ -64,48 +120,88 @@ extern char *stpncpy (char *restrict __dst, char const *restrict __src,
    No known system has a strcasecmp() function that works correctly in
    multibyte locales.  Therefore use our version always, if the
    strcase module is available.  */
-#if @REPLACE_STRCASECMP@
-# define strcasecmp rpl_strcasecmp
+#if @GNULIB_STRCASE@
+# if @REPLACE_STRCASECMP@
+#  define strcasecmp rpl_strcasecmp
 extern int strcasecmp (char const *__s1, char const *__s2);
+# endif
+#elif defined GNULIB_POSIXCHECK
+# undef strcasecmp
+# define strcasecmp(a,b) \
+    (GL_LINK_WARNING ("strcasecmp is often incorrectly implemented for multibyte locales - use gnulib module 'strcase' for correct and portable internationalization"), \
+     strcasecmp (a, b))
 #endif
 
 /* Compare no more than N bytes of strings S1 and S2, ignoring case,
    returning less than, equal to or greater than zero if S1 is
    lexicographically less than, equal to or greater than S2.
    Note: This function cannot work correctly in multibyte locales.  */
-#if ! @HAVE_DECL_STRNCASECMP@
+#if @GNULIB_STRCASE@
+# if ! @HAVE_DECL_STRNCASECMP@
 extern int strncasecmp (char const *__s1, char const *__s2, size_t __n);
+# endif
+#endif
+#if defined GNULIB_POSIXCHECK
+# undef strncasecmp
+# define strncasecmp(a,b) \
+    (GL_LINK_WARNING ("strncasecmp cannot work correctly in multibyte locales - don't use it if you care about internationalization"), \
+     strncasecmp (a, b))
 #endif
 
 /* Find the first occurrence of C in S or the final NUL byte.  */
-#if ! @HAVE_STRCHRNUL@
+#if @GNULIB_STRCHRNUL@
+# if ! @HAVE_STRCHRNUL@
 extern char *strchrnul (char const *__s, int __c_in);
+# endif
+#elif defined GNULIB_POSIXCHECK
+# undef strchrnul
+# define strchrnul strchrnul_is_unportable__use_gnulib_module_strchrnul_for_portability
 #endif
 
 /* Duplicate S, returning an identical malloc'd string.  */
-#if ! @HAVE_DECL_STRDUP@ && ! defined strdup
+#if @GNULIB_STRDUP@
+# if ! @HAVE_DECL_STRDUP@ && ! defined strdup
 extern char *strdup (char const *__s);
+# endif
+#elif defined GNULIB_POSIXCHECK
+# undef strdup
+# define strdup strdup_is_unportable__use_gnulib_module_strdup_for_portability
 #endif
 
 /* Return a newly allocated copy of at most N bytes of STRING.  */
-#if ! @HAVE_STRNDUP@
-# undef strndup
-# define strndup rpl_strndup
-# if ! @HAVE_DECL_STRNDUP@
+#if @GNULIB_STRNDUP@
+# if ! @HAVE_STRNDUP@
+#  undef strndup
+#  define strndup rpl_strndup
+#  if ! @HAVE_DECL_STRNDUP@
 extern char *strndup (char const *__string, size_t __n);
+#  endif
 # endif
+#elif defined GNULIB_POSIXCHECK
+# undef strndup
+# define strndup strndup_is_unportable__use_gnulib_module_strndup_for_portability
 #endif
 
 /* Find the length (number of bytes) of STRING, but scan at most
    MAXLEN bytes.  If no '\0' terminator is found in that many bytes,
    return MAXLEN.  */
-#if ! @HAVE_DECL_STRNLEN@
+#if @GNULIB_STRNLEN@
+# if ! @HAVE_DECL_STRNLEN@
 extern size_t strnlen (char const *__string, size_t __maxlen);
+# endif
+#elif defined GNULIB_POSIXCHECK
+# undef strnlen
+# define strnlen strnlen_is_unportable__use_gnulib_module_strnlen_for_portability
 #endif
 
 /* Find the first occurrence in S of any character in ACCEPT.  */
-#if ! @HAVE_STRPBRK@
+#if @GNULIB_STRPBRK@
+# if ! @HAVE_STRPBRK@
 extern char *strpbrk (char const *__s, char const *__accept);
+# endif
+#elif defined GNULIB_POSIXCHECK
+# undef strpbrk
+# define strpbrk strpbrk_is_unportable__use_gnulib_module_strpbrk_for_portability
 #endif
 
 /* Search the next delimiter (char listed in DELIM) starting at *STRINGP.
@@ -124,28 +220,47 @@ extern char *strpbrk (char const *__s, char const *__accept);
            characters are ASCII characters < 0x30.
 
    See also strtok_r().  */
-#if ! @HAVE_STRSEP@
+#if @GNULIB_STRSEP@
+# if ! @HAVE_STRSEP@
 extern char *strsep (char **restrict __stringp, char const *restrict __delim);
+# endif
+#elif defined GNULIB_POSIXCHECK
+# undef strsep
+# define strsep strsep_is_unportable__use_gnulib_module_strsep_for_portability
 #endif
 
 /* Find the first occurrence of NEEDLE in HAYSTACK.
    No known system has a strstr() function that works correctly in
    multibyte locales.  Therefore use our version always, if the strstr
    module is available.  */
-#if @REPLACE_STRSTR@
-# undef strstr
-# define strstr rpl_strstr
+#if @GNULIB_STRSTR@
+# if @REPLACE_STRSTR@
+#  undef strstr
+#  define strstr rpl_strstr
 extern char *strstr (char const *__haystack, char const *__needle);
+# endif
+#elif defined GNULIB_POSIXCHECK
+# undef strstr
+# define strstr(a,b) \
+    (GL_LINK_WARNING ("strstr is often incorrectly implemented for multibyte locales - use gnulib module 'strstr' for correct and portable internationalization"), \
+     strstr (a, b))
 #endif
 
 /* Find the first occurrence of NEEDLE in HAYSTACK, using case-insensitive
    comparison.
    Note: This function may, in multibyte locales, return success even if
    strlen (haystack) < strlen (needle) !  */
-#if @REPLACE_STRCASESTR@
-# undef strcasestr
-# define strcasestr rpl_strcasestr
+#if @GNULIB_STRCASESTR@
+# if @REPLACE_STRCASESTR@
+#  undef strcasestr
+#  define strcasestr rpl_strcasestr
 extern char *strcasestr (const char *haystack, const char *needle);
+# endif
+#elif defined GNULIB_POSIXCHECK
+# undef strcasestr
+# define strcasestr(a,b) \
+    (GL_LINK_WARNING ("strcasestr is often incorrectly implemented for multibyte locales - use gnulib module 'strcasestr' for correct and portable internationalization"), \
+     strcasestr (a, b))
 #endif
 
 /* Parse S into tokens separated by characters in DELIM.
@@ -170,9 +285,14 @@ extern char *strcasestr (const char *haystack, const char *needle);
            characters are ASCII characters < 0x30.
 
    See also strsep().  */
-#if ! @HAVE_DECL_STRTOK_R@
+#if @GNULIB_STRTOK_R@
+# if ! @HAVE_DECL_STRTOK_R@
 extern char *strtok_r (char *restrict __s, char const *restrict __sep,
 		       char **restrict __lasts);
+# endif
+#elif defined GNULIB_POSIXCHECK
+# undef strtok_r
+# define strtok_r strtok_r_is_unportable__use_gnulib_module_strtok_r_for_portability
 #endif
 
 #ifdef __cplusplus
diff --git a/lgl/Makefile.am b/lgl/Makefile.am
index 7db8b8dc8e..c977a161ba 100644
--- a/lgl/Makefile.am
+++ b/lgl/Makefile.am
@@ -281,6 +281,21 @@ string.h: string_.h
 	rm -f $@-t $@
 	{ echo '/* DO NOT EDIT! GENERATED AUTOMATICALLY! */' && \
 	  sed -e 's|@''ABSOLUTE_STRING_H''@|$(ABSOLUTE_STRING_H)|g' \
+	      -e 's|@''GNULIB_MEMMEM''@|$(GNULIB_MEMMEM)|g' \
+	      -e 's|@''GNULIB_MEMPCPY''@|$(GNULIB_MEMPCPY)|g' \
+	      -e 's|@''GNULIB_MEMRCHR''@|$(GNULIB_MEMRCHR)|g' \
+	      -e 's|@''GNULIB_STPCPY''@|$(GNULIB_STPCPY)|g' \
+	      -e 's|@''GNULIB_STPNCPY''@|$(GNULIB_STPNCPY)|g' \
+	      -e 's|@''GNULIB_STRCASE''@|$(GNULIB_STRCASE)|g' \
+	      -e 's|@''GNULIB_STRCHRNUL''@|$(GNULIB_STRCHRNUL)|g' \
+	      -e 's|@''GNULIB_STRDUP''@|$(GNULIB_STRDUP)|g' \
+	      -e 's|@''GNULIB_STRNDUP''@|$(GNULIB_STRNDUP)|g' \
+	      -e 's|@''GNULIB_STRNLEN''@|$(GNULIB_STRNLEN)|g' \
+	      -e 's|@''GNULIB_STRPBRK''@|$(GNULIB_STRPBRK)|g' \
+	      -e 's|@''GNULIB_STRSEP''@|$(GNULIB_STRSEP)|g' \
+	      -e 's|@''GNULIB_STRSTR''@|$(GNULIB_STRSTR)|g' \
+	      -e 's|@''GNULIB_STRCASESTR''@|$(GNULIB_STRCASESTR)|g' \
+	      -e 's|@''GNULIB_STRTOK_R''@|$(GNULIB_STRTOK_R)|g' \
 	      -e 's|@''HAVE_DECL_MEMMEM''@|$(HAVE_DECL_MEMMEM)|g' \
 	      -e 's|@''HAVE_MEMPCPY''@|$(HAVE_MEMPCPY)|g' \
 	      -e 's|@''HAVE_DECL_MEMRCHR''@|$(HAVE_DECL_MEMRCHR)|g' \
diff --git a/lgl/m4/gnulib-comp.m4 b/lgl/m4/gnulib-comp.m4
index 3ebad02bf5..87028debd9 100644
--- a/lgl/m4/gnulib-comp.m4
+++ b/lgl/m4/gnulib-comp.m4
@@ -74,6 +74,7 @@ AC_DEFUN([lgl_INIT],
   AM_GNU_GETTEXT_VERSION([0.15])
   gl_MD2
   gl_FUNC_MEMMEM
+  gl_STRING_MODULE_INDICATOR([memmem])
   gl_FUNC_MEMMOVE
   gl_MINMAX
   gl_FUNC_READ_FILE
diff --git a/lgl/m4/socklen.m4 b/lgl/m4/socklen.m4
index 5e3765a64b..e824a09f56 100644
--- a/lgl/m4/socklen.m4
+++ b/lgl/m4/socklen.m4
@@ -1,5 +1,5 @@
-# socklen.m4 serial 4
-dnl Copyright (C) 2005, 2006 Free Software Foundation, Inc.
+# socklen.m4 serial 5
+dnl Copyright (C) 2005, 2006, 2007 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
 dnl with or without modifications, as long as this notice is preserved.
@@ -19,7 +19,7 @@ AC_DEFUN([gl_TYPE_SOCKLEN_T],
   [AC_REQUIRE([gl_HEADER_SYS_SOCKET])dnl
    AC_CHECK_TYPE([socklen_t], ,
      [AC_MSG_CHECKING([for socklen_t equivalent])
-      AC_CACHE_VAL([gl_cv_gl_cv_socklen_t_equiv],
+      AC_CACHE_VAL([gl_cv_socklen_t_equiv],
 	[# Systems have either "struct sockaddr *" or
 	 # "void *" as the second argument to getpeername
 	 gl_cv_socklen_t_equiv=
diff --git a/lgl/m4/string_h.m4 b/lgl/m4/string_h.m4
index 84db7a59ba..8e0be44f85 100644
--- a/lgl/m4/string_h.m4
+++ b/lgl/m4/string_h.m4
@@ -18,6 +18,7 @@ AC_DEFUN([gl_HEADER_STRING_H_BODY],
 [
   AC_REQUIRE([AC_C_RESTRICT])
   AC_REQUIRE([gl_HEADER_STRING_H_DEFAULTS])
+  AC_REQUIRE([gl_STRING_MODULE_INDICATOR_DEFAULTS])
   gl_ABSOLUTE_HEADER([string.h])
   ABSOLUTE_STRING_H=\"$gl_cv_absolute_string_h\"
   AC_SUBST([ABSOLUTE_STRING_H])
@@ -44,3 +45,29 @@ AC_DEFUN([gl_HEADER_STRING_H_DEFAULTS],
   REPLACE_STRSTR=0;		AC_SUBST([REPLACE_STRSTR])
   REPLACE_STRCASESTR=0;		AC_SUBST([REPLACE_STRCASESTR])
 ])
+
+AC_DEFUN([gl_STRING_MODULE_INDICATOR],
+[
+  dnl Use AC_REQUIRE here, so that the default settings are expanded once only.
+  AC_REQUIRE([gl_STRING_MODULE_INDICATOR_DEFAULTS])
+  GNULIB_[]m4_translit([$1],[abcdefghijklmnopqrstuvwxyz./-],[ABCDEFGHIJKLMNOPQRSTUVWXYZ___])=1
+])
+
+AC_DEFUN([gl_STRING_MODULE_INDICATOR_DEFAULTS],
+[
+  GNULIB_MEMMEM=0;      AC_SUBST([GNULIB_MEMMEM])
+  GNULIB_MEMPCPY=0;     AC_SUBST([GNULIB_MEMPCPY])
+  GNULIB_MEMRCHR=0;     AC_SUBST([GNULIB_MEMRCHR])
+  GNULIB_STPCPY=0;      AC_SUBST([GNULIB_STPCPY])
+  GNULIB_STPNCPY=0;     AC_SUBST([GNULIB_STPNCPY])
+  GNULIB_STRCASE=0;     AC_SUBST([GNULIB_STRCASE])
+  GNULIB_STRCHRNUL=0;   AC_SUBST([GNULIB_STRCHRNUL])
+  GNULIB_STRDUP=0;      AC_SUBST([GNULIB_STRDUP])
+  GNULIB_STRNDUP=0;     AC_SUBST([GNULIB_STRNDUP])
+  GNULIB_STRNLEN=0;     AC_SUBST([GNULIB_STRNLEN])
+  GNULIB_STRPBRK=0;     AC_SUBST([GNULIB_STRPBRK])
+  GNULIB_STRSEP=0;      AC_SUBST([GNULIB_STRSEP])
+  GNULIB_STRSTR=0;      AC_SUBST([GNULIB_STRSTR])
+  GNULIB_STRCASESTR=0;  AC_SUBST([GNULIB_STRCASESTR])
+  GNULIB_STRTOK_R=0;    AC_SUBST([GNULIB_STRTOK_R])
+])
diff --git a/lgl/string_.h b/lgl/string_.h
index 617a51b9df..b99461a0b3 100644
--- a/lgl/string_.h
+++ b/lgl/string_.h
@@ -21,39 +21,95 @@
 
 #include @ABSOLUTE_STRING_H@
 
+
+/* GL_LINK_WARNING("literal string") arranges to emit the literal string as
+   a linker warning on most glibc systems.
+   We use a linker warning rather than a preprocessor warning, because
+   #warning cannot be used inside macros.  */
+#ifndef GL_LINK_WARNING
+  /* This works on platforms with GNU ld and ELF object format.
+     Testing __GLIBC__ is sufficient for asserting that GNU ld is in use.
+     Testing __ELF__ guarantees the ELF object format.
+     Testing __GNUC__ is necessary for the compound expression syntax.  */
+# if defined __GLIBC__ && defined __ELF__ && defined __GNUC__
+#  define GL_LINK_WARNING(message) \
+     GL_LINK_WARNING1 (__FILE__, __LINE__, message)
+#  define GL_LINK_WARNING1(file, line, message) \
+     GL_LINK_WARNING2 (file, line, message)  /* macroexpand file and line */
+#  define GL_LINK_WARNING2(file, line, message) \
+     GL_LINK_WARNING3 (file ":" #line ": " message)
+#  define GL_LINK_WARNING3(message) \
+     ({ static const char warning[sizeof (message)]		\
+          __attribute__ ((__unused__,				\
+                          __section__ (".gnu.warning"),		\
+                          __aligned__ (1)))			\
+          = message "\n";					\
+        (void)0;						\
+     })
+# else
+#  define GL_LINK_WARNING(message) ((void) 0)
+# endif
+#endif
+
+
 #ifdef __cplusplus
 extern "C" {
 #endif
 
 /* Return the first occurrence of NEEDLE in HAYSTACK.  */
-#if ! @HAVE_DECL_MEMMEM@
+#if @GNULIB_MEMMEM@
+# if ! @HAVE_DECL_MEMMEM@
 extern void *memmem (void const *__haystack, size_t __haystack_len,
 		     void const *__needle, size_t __needle_len);
+# endif
+#elif defined GNULIB_POSIXCHECK
+# undef memmem
+# define memmem memmem_is_unportable__use_gnulib_module_memmem_for_portability
 #endif
 
 /* Copy N bytes of SRC to DEST, return pointer to bytes after the
    last written byte.  */
-#if ! @HAVE_MEMPCPY@
+#if @GNULIB_MEMPCPY@
+# if ! @HAVE_MEMPCPY@
 extern void *mempcpy (void *restrict __dest, void const *restrict __src,
 		      size_t __n);
+# endif
+#elif defined GNULIB_POSIXCHECK
+# undef mempcpy
+# define mempcpy mempcpy_is_unportable__use_gnulib_module_mempcpy_for_portability
 #endif
 
 /* Search backwards through a block for a byte (specified as an int).  */
-#if ! @HAVE_DECL_MEMRCHR@
+#if @GNULIB_MEMRCHR@
+# if ! @HAVE_DECL_MEMRCHR@
 extern void *memrchr (void const *, int, size_t);
+# endif
+#elif defined GNULIB_POSIXCHECK
+# undef memrchr
+# define memrchr memrchr_is_unportable__use_gnulib_module_memrchr_for_portability
 #endif
 
 /* Copy SRC to DST, returning the address of the terminating '\0' in DST.  */
-#if ! @HAVE_STPCPY@
+#if @GNULIB_STPCPY@
+# if ! @HAVE_STPCPY@
 extern char *stpcpy (char *restrict __dst, char const *restrict __src);
+# endif
+#elif defined GNULIB_POSIXCHECK
+# undef stpcpy
+# define stpcpy stpcpy_is_unportable__use_gnulib_module_stpcpy_for_portability
 #endif
 
 /* Copy no more than N bytes of SRC to DST, returning a pointer past the
    last non-NUL byte written into DST.  */
-#if ! @HAVE_STPNCPY@
-# define stpncpy gnu_stpncpy
+#if @GNULIB_STPNCPY@
+# if ! @HAVE_STPNCPY@
+#  define stpncpy gnu_stpncpy
 extern char *stpncpy (char *restrict __dst, char const *restrict __src,
 		      size_t __n);
+# endif
+#elif defined GNULIB_POSIXCHECK
+# undef stpncpy
+# define stpncpy stpncpy_is_unportable__use_gnulib_module_stpncpy_for_portability
 #endif
 
 /* Compare strings S1 and S2, ignoring case, returning less than, equal to or
@@ -64,48 +120,88 @@ extern char *stpncpy (char *restrict __dst, char const *restrict __src,
    No known system has a strcasecmp() function that works correctly in
    multibyte locales.  Therefore use our version always, if the
    strcase module is available.  */
-#if @REPLACE_STRCASECMP@
-# define strcasecmp rpl_strcasecmp
+#if @GNULIB_STRCASE@
+# if @REPLACE_STRCASECMP@
+#  define strcasecmp rpl_strcasecmp
 extern int strcasecmp (char const *__s1, char const *__s2);
+# endif
+#elif defined GNULIB_POSIXCHECK
+# undef strcasecmp
+# define strcasecmp(a,b) \
+    (GL_LINK_WARNING ("strcasecmp is often incorrectly implemented for multibyte locales - use gnulib module 'strcase' for correct and portable internationalization"), \
+     strcasecmp (a, b))
 #endif
 
 /* Compare no more than N bytes of strings S1 and S2, ignoring case,
    returning less than, equal to or greater than zero if S1 is
    lexicographically less than, equal to or greater than S2.
    Note: This function cannot work correctly in multibyte locales.  */
-#if ! @HAVE_DECL_STRNCASECMP@
+#if @GNULIB_STRCASE@
+# if ! @HAVE_DECL_STRNCASECMP@
 extern int strncasecmp (char const *__s1, char const *__s2, size_t __n);
+# endif
+#endif
+#if defined GNULIB_POSIXCHECK
+# undef strncasecmp
+# define strncasecmp(a,b) \
+    (GL_LINK_WARNING ("strncasecmp cannot work correctly in multibyte locales - don't use it if you care about internationalization"), \
+     strncasecmp (a, b))
 #endif
 
 /* Find the first occurrence of C in S or the final NUL byte.  */
-#if ! @HAVE_STRCHRNUL@
+#if @GNULIB_STRCHRNUL@
+# if ! @HAVE_STRCHRNUL@
 extern char *strchrnul (char const *__s, int __c_in);
+# endif
+#elif defined GNULIB_POSIXCHECK
+# undef strchrnul
+# define strchrnul strchrnul_is_unportable__use_gnulib_module_strchrnul_for_portability
 #endif
 
 /* Duplicate S, returning an identical malloc'd string.  */
-#if ! @HAVE_DECL_STRDUP@ && ! defined strdup
+#if @GNULIB_STRDUP@
+# if ! @HAVE_DECL_STRDUP@ && ! defined strdup
 extern char *strdup (char const *__s);
+# endif
+#elif defined GNULIB_POSIXCHECK
+# undef strdup
+# define strdup strdup_is_unportable__use_gnulib_module_strdup_for_portability
 #endif
 
 /* Return a newly allocated copy of at most N bytes of STRING.  */
-#if ! @HAVE_STRNDUP@
-# undef strndup
-# define strndup rpl_strndup
-# if ! @HAVE_DECL_STRNDUP@
+#if @GNULIB_STRNDUP@
+# if ! @HAVE_STRNDUP@
+#  undef strndup
+#  define strndup rpl_strndup
+#  if ! @HAVE_DECL_STRNDUP@
 extern char *strndup (char const *__string, size_t __n);
+#  endif
 # endif
+#elif defined GNULIB_POSIXCHECK
+# undef strndup
+# define strndup strndup_is_unportable__use_gnulib_module_strndup_for_portability
 #endif
 
 /* Find the length (number of bytes) of STRING, but scan at most
    MAXLEN bytes.  If no '\0' terminator is found in that many bytes,
    return MAXLEN.  */
-#if ! @HAVE_DECL_STRNLEN@
+#if @GNULIB_STRNLEN@
+# if ! @HAVE_DECL_STRNLEN@
 extern size_t strnlen (char const *__string, size_t __maxlen);
+# endif
+#elif defined GNULIB_POSIXCHECK
+# undef strnlen
+# define strnlen strnlen_is_unportable__use_gnulib_module_strnlen_for_portability
 #endif
 
 /* Find the first occurrence in S of any character in ACCEPT.  */
-#if ! @HAVE_STRPBRK@
+#if @GNULIB_STRPBRK@
+# if ! @HAVE_STRPBRK@
 extern char *strpbrk (char const *__s, char const *__accept);
+# endif
+#elif defined GNULIB_POSIXCHECK
+# undef strpbrk
+# define strpbrk strpbrk_is_unportable__use_gnulib_module_strpbrk_for_portability
 #endif
 
 /* Search the next delimiter (char listed in DELIM) starting at *STRINGP.
@@ -124,28 +220,47 @@ extern char *strpbrk (char const *__s, char const *__accept);
            characters are ASCII characters < 0x30.
 
    See also strtok_r().  */
-#if ! @HAVE_STRSEP@
+#if @GNULIB_STRSEP@
+# if ! @HAVE_STRSEP@
 extern char *strsep (char **restrict __stringp, char const *restrict __delim);
+# endif
+#elif defined GNULIB_POSIXCHECK
+# undef strsep
+# define strsep strsep_is_unportable__use_gnulib_module_strsep_for_portability
 #endif
 
 /* Find the first occurrence of NEEDLE in HAYSTACK.
    No known system has a strstr() function that works correctly in
    multibyte locales.  Therefore use our version always, if the strstr
    module is available.  */
-#if @REPLACE_STRSTR@
-# undef strstr
-# define strstr rpl_strstr
+#if @GNULIB_STRSTR@
+# if @REPLACE_STRSTR@
+#  undef strstr
+#  define strstr rpl_strstr
 extern char *strstr (char const *__haystack, char const *__needle);
+# endif
+#elif defined GNULIB_POSIXCHECK
+# undef strstr
+# define strstr(a,b) \
+    (GL_LINK_WARNING ("strstr is often incorrectly implemented for multibyte locales - use gnulib module 'strstr' for correct and portable internationalization"), \
+     strstr (a, b))
 #endif
 
 /* Find the first occurrence of NEEDLE in HAYSTACK, using case-insensitive
    comparison.
    Note: This function may, in multibyte locales, return success even if
    strlen (haystack) < strlen (needle) !  */
-#if @REPLACE_STRCASESTR@
-# undef strcasestr
-# define strcasestr rpl_strcasestr
+#if @GNULIB_STRCASESTR@
+# if @REPLACE_STRCASESTR@
+#  undef strcasestr
+#  define strcasestr rpl_strcasestr
 extern char *strcasestr (const char *haystack, const char *needle);
+# endif
+#elif defined GNULIB_POSIXCHECK
+# undef strcasestr
+# define strcasestr(a,b) \
+    (GL_LINK_WARNING ("strcasestr is often incorrectly implemented for multibyte locales - use gnulib module 'strcasestr' for correct and portable internationalization"), \
+     strcasestr (a, b))
 #endif
 
 /* Parse S into tokens separated by characters in DELIM.
@@ -170,9 +285,14 @@ extern char *strcasestr (const char *haystack, const char *needle);
            characters are ASCII characters < 0x30.
 
    See also strsep().  */
-#if ! @HAVE_DECL_STRTOK_R@
+#if @GNULIB_STRTOK_R@
+# if ! @HAVE_DECL_STRTOK_R@
 extern char *strtok_r (char *restrict __s, char const *restrict __sep,
 		       char **restrict __lasts);
+# endif
+#elif defined GNULIB_POSIXCHECK
+# undef strtok_r
+# define strtok_r strtok_r_is_unportable__use_gnulib_module_strtok_r_for_portability
 #endif
 
 #ifdef __cplusplus