Fix iconv detection on OpenBSD

Matthias Kilian discovered that iconv_open is #define'd to something
else on OpenBSD, so the test needs to include the iconv header.

2 files changed, 52 insertions, 2 deletions

diff --git a/libraries/base/aclocal.m4 b/libraries/base/aclocal.m4
index 615cbe1456..d40392ace3 100644
--- a/libraries/base/aclocal.m4
+++ b/libraries/base/aclocal.m4
@@ -228,3 +228,39 @@ char **argv;
 [fptools_cv_readdir_eof_errno=0])])
 AC_DEFINE_UNQUOTED([READDIR_ERRNO_EOF], [$fptools_cv_readdir_eof_errno], [readdir() sets errno to this upon EOF])
 ])# FP_READDIR_EOF_ERRNO
+
+# FP_SEARCH_LIBS_PROTO(WHAT, PROTOTYPE, FUNCTION, SEARCH-LIBS,
+#                [ACTION-IF-FOUND], [ACTION-IF-NOT-FOUND],
+#                [OTHER-LIBRARIES])
+# --------------------------------------------------------
+# Search for a library defining FUNC, if it's not already available.
+# This is a copy of the AC_SEARCH_LIBS definition, but extended to take
+# the name of the thing we are looking for as its first argument, and
+# prototype text as its second argument. It also calls AC_LANG_PROGRAM
+# instead of AC_LANG_CALL
+AC_DEFUN([FP_SEARCH_LIBS_PROTO],
+[AS_VAR_PUSHDEF([ac_Search], [ac_cv_search_$3])dnl
+AC_CACHE_CHECK([for library containing $1], [ac_Search],
+[ac_func_search_save_LIBS=$LIBS
+AC_LANG_CONFTEST([AC_LANG_PROGRAM([$2], [$3])])
+for ac_lib in '' $4; do
+  if test -z "$ac_lib"; then
+    ac_res="none required"
+  else
+    ac_res=-l$ac_lib
+    LIBS="-l$ac_lib $7 $ac_func_search_save_LIBS"
+  fi
+  AC_LINK_IFELSE([], [AS_VAR_SET([ac_Search], [$ac_res])])
+  AS_VAR_SET_IF([ac_Search], [break])dnl
+done
+AS_VAR_SET_IF([ac_Search], , [AS_VAR_SET([ac_Search], [no])])dnl
+rm conftest.$ac_ext
+LIBS=$ac_func_search_save_LIBS])
+ac_res=AS_VAR_GET([ac_Search])
+AS_IF([test "$ac_res" != no],
+  [test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
+  $5],
+      [$6])dnl
+AS_VAR_POPDEF([ac_Search])dnl
+])
+
diff --git a/libraries/base/configure.ac b/libraries/base/configure.ac
index cd153c3bc0..ce85ed010f 100644
--- a/libraries/base/configure.ac
+++ b/libraries/base/configure.ac
@@ -99,8 +99,22 @@ FP_CHECK_CONST([O_BINARY], [#include <fcntl.h>], [0])
 # Check for idiosyncracies in some mingw impls of directory handling.
 FP_READDIR_EOF_ERRNO
 
-AC_CHECK_LIB(iconv, iconv_open,
-    [EXTRA_LIBS="$EXTRA_LIBS iconv"])
+# We can't just use AC_SEARCH_LIBS for this, as on OpenBSD the iconv.h
+# header needs to be included as iconv_open is #define'd to something
+# else. We therefore use our own FP_SEARCH_LIBS_PROTO, which allows us
+# to give prototype text.
+FP_SEARCH_LIBS_PROTO(iconv,
+                     [
+#include <stddef.h>
+#include <iconv.h>
+                      ],
+                     [iconv_t cd;
+                      cd = iconv_open("", "");
+                      iconv(cd,NULL,NULL,NULL,NULL);
+                      iconv_close(cd);],
+                     iconv,
+                     [EXTRA_LIBS="$EXTRA_LIBS $ac_lib"],
+                     [exit 1])
 
 AC_SUBST(EXTRA_LIBS)
 AC_CONFIG_FILES([base.buildinfo])