[krb5-auth-dialog] check for krb5_free_error_message

[Guido Günther <guidog src gnome org>]

commit 126657ebfddb23aa3e3aa18f25f4afae00ecc24d
Author: Guido Günther <agx sigxcpu org>
Date:   Thu Sep 17 00:33:57 2009 +0200

    check for krb5_free_error_message
    
    and make krb5_get_error_message mandatory. Fixes build with MIT
    Kerberos.

 configure.ac           |    5 ++++-
 src/krb5-auth-dialog.c |   20 ++++++++++++++++----
 2 files changed, 20 insertions(+), 5 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index dd9115b..cf601d3 100644
--- a/configure.ac
+++ b/configure.ac
@@ -87,7 +87,10 @@ AC_CHECK_MEMBERS(krb5_creds.flags.b.forwardable,,,[#include <krb5.h>])
 AC_CHECK_MEMBERS(krb5_creds.flags.b.renewable,,,[#include <krb5.h>])
 AC_CHECK_MEMBERS(krb5_creds.flags.b.proxiable,,,[#include <krb5.h>])
 AC_CHECK_MEMBERS(krb5_creds.flags,,,[#include <krb5.h>])
-AC_CHECK_FUNCS([krb5_get_error_message krb5_get_renewed_creds \
+AC_CHECK_FUNCS([krb5_get_error_message \
+                krb5_free_error_message \
+                krb5_free_error_string \
+                krb5_get_renewed_creds \
                 krb5_get_init_creds_opt_set_default_flags \
                 krb5_cc_clear_mcred])
 AC_CHECK_FUNCS([krb5_get_init_creds_opt_set_pkinit],
diff --git a/src/krb5-auth-dialog.c b/src/krb5-auth-dialog.c
index 46e2317..b8f95c2 100644
--- a/src/krb5-auth-dialog.c
+++ b/src/krb5-auth-dialog.c
@@ -139,22 +139,34 @@ get_principal_realm_data(krb5_principal p)
 #endif
 }
 
+static void
+ka_krb5_free_error_message(krb5_context context, const char* msg)
+{
+#if defined(HAVE_KRB5_FREE_ERROR_MESSAGE)
+	krb5_free_error_message(context, msg);
+#elif defined(HAVE_KRB5_FREE_ERROR_STRING)
+	krb5_free_error_string(context, (char *) msg);
+#else
+#	error No way to free error string.
+#endif
+}
+
 /*
  * Returns a descriptive error message or kerberos related error
- * pointer must be freed using g_free()
+ * returned pointer must be freed using g_free().
  */
 static char*
 ka_get_error_message(krb5_context context, krb5_error_code err)
 {
 	char *msg = NULL;
 #if defined(HAVE_KRB5_GET_ERROR_MESSAGE)
-	char *krberr;
+	const char *krberr;
 
 	krberr = krb5_get_error_message(context, err);
 	msg = g_strdup(krberr);
-	krb5_free_error_string(context, krberr);
+	ka_krb5_free_error_message(context, krberr);
 #else
-	msg = g_strdup(error_message(err));
+#	error No detailed error message information
 #endif
 	if (msg == NULL)
 		msg = g_strdup(_("unknown error"));