M configure.in → configure.in

@@ -63,7 +63,7 @@ AC_MSG_RESULT(yes)
 ],
 [AC_MSG_RESULT(no)])
 
-AC_MSG_CHECKING([iconv])
+AC_MSG_CHECKING([for iconv])
 AC_TRY_COMPILE(
 [#include <iconv.h>],
 [iconv_t cd = iconv_open("", "")],
@@ -72,7 +72,18 @@ HAVE_ICONV=no)
 
 if test x"$HAVE_ICONV" = x"yes"; then
     AC_DEFINE(HAVE_ICONV, 1, "iconv")
-    AC_MSG_RESULT([yes])
+dnl now check for const char *msg argument in iconv(..)
+    AC_TRY_COMPILE(
+    [#include <iconv.h>],
+    [
+        char **msg, **new_msg; 
+        size_t result, inleft, outleft; 
+        result = iconv((iconv_t)(-1), msg, &inleft, new_msg, &outleft);
+        return 0;
+    ],
+    [ AC_MSG_RESULT([yes (non const msg)])],
+    [ AC_DEFINE(HAVE_CONST_ICONV, 1, "iconv")
+      AC_MSG_RESULT([yes (const msg)])])
 else
     AC_MSG_RESULT([no])
 fi