diff --git a/modules/aaa/mod_auth_digest.c b/modules/aaa/mod_auth_digest.c

index 44b5fc8..6a50ba7 100644

--- a/modules/aaa/mod_auth_digest.c

+++ b/modules/aaa/mod_auth_digest.c

@@ -261,6 +261,26 @@ static void log_error_and_cleanup(char *msg, apr_status_t sts, server_rec *s)

     cleanup_tables(NULL);

 }

+/* RMM helper functions that behave like single-step malloc/free. */

+

+static void *rmm_malloc(apr_rmm_t *rmm, apr_size_t size)

+{

+    apr_rmm_off_t offset = apr_rmm_malloc(rmm, size);

+

+    if (!offset) {

+        return NULL;

+    }

+

+    return apr_rmm_addr_get(rmm, offset);

+}

+

+static apr_status_t rmm_free(apr_rmm_t *rmm, void *alloc)

+{

+    apr_rmm_off_t offset = apr_rmm_offset_get(rmm, alloc);

+

+    return apr_rmm_free(rmm, offset);

+}

+

 #if APR_HAS_SHARED_MEMORY

 static int initialize_tables(server_rec *s, apr_pool_t *ctx)

@@ -299,8 +319,8 @@ static int initialize_tables(server_rec *s, apr_pool_t *ctx)

         return !OK;

     }

-    client_list = apr_rmm_addr_get(client_rmm, apr_rmm_malloc(client_rmm, sizeof(*client_list) +

-                                                          sizeof(client_entry*)*num_buckets));

+    client_list = rmm_malloc(client_rmm, sizeof(*client_list) +

+                                         sizeof(client_entry *) * num_buckets);

     if (!client_list) {

         log_error_and_cleanup("failed to allocate shared memory", -1, s);

         return !OK;

@@ -322,7 +342,7 @@ static int initialize_tables(server_rec *s, apr_pool_t *ctx)

     /* setup opaque */

-    opaque_cntr = apr_rmm_addr_get(client_rmm, apr_rmm_malloc(client_rmm, sizeof(*opaque_cntr)));

+    opaque_cntr = rmm_malloc(client_rmm, sizeof(*opaque_cntr));

     if (opaque_cntr == NULL) {

         log_error_and_cleanup("failed to allocate shared memory", -1, s);

         return !OK;

@@ -339,7 +359,7 @@ static int initialize_tables(server_rec *s, apr_pool_t *ctx)

     /* setup one-time-nonce counter */

-    otn_counter = apr_rmm_addr_get(client_rmm, apr_rmm_malloc(client_rmm, sizeof(*otn_counter)));

+    otn_counter = rmm_malloc(client_rmm, sizeof(*otn_counter));

     if (otn_counter == NULL) {

         log_error_and_cleanup("failed to allocate shared memory", -1, s);

         return !OK;

@@ -779,7 +799,7 @@ static client_entry *get_client(unsigned long key, const request_rec *r)

  * last entry in each bucket and updates the counters. Returns the

  * number of removed entries.

  */

-static long gc(void)

+static long gc(server_rec *s)

 {

     client_entry *entry, *prev;

     unsigned long num_removed = 0, idx;

@@ -789,6 +809,12 @@ static long gc(void)

     for (idx = 0; idx < client_list->tbl_len; idx++) {

         entry = client_list->table[idx];

         prev  = NULL;

+

+        if (!entry) {

+            /* This bucket is empty. */

+            continue;

+        }

+

         while (entry->next) {   /* find last entry */

             prev  = entry;

             entry = entry->next;

@@ -800,8 +826,16 @@ static long gc(void)

             client_list->table[idx] = NULL;

         }

         if (entry) {                    /* remove entry */

-            apr_rmm_free(client_rmm, apr_rmm_offset_get(client_rmm, entry));

+            apr_status_t err;

+

+            err = rmm_free(client_rmm, entry);

             num_removed++;

+

+            if (err) {

+                /* Nothing we can really do but log... */

+                ap_log_error(APLOG_MARK, APLOG_ERR, err, s, APLOGNO()

+                             "Failed to free auth_digest client allocation");

+            }

         }

     }

@@ -835,16 +869,16 @@ static client_entry *add_client(unsigned long key, client_entry *info,

     /* try to allocate a new entry */

-    entry = apr_rmm_addr_get(client_rmm, apr_rmm_malloc(client_rmm, sizeof(client_entry)));

+    entry = rmm_malloc(client_rmm, sizeof(client_entry));

     if (!entry) {

-        long num_removed = gc();

+        long num_removed = gc(s);

         ap_log_error(APLOG_MARK, APLOG_INFO, 0, s, APLOGNO(01766)

                      "gc'd %ld client entries. Total new clients: "

                      "%ld; Total removed clients: %ld; Total renewed clients: "

                      "%ld", num_removed,

                      client_list->num_created - client_list->num_renewed,

                      client_list->num_removed, client_list->num_renewed);

-        entry = apr_rmm_addr_get(client_rmm, apr_rmm_malloc(client_rmm, sizeof(client_entry)));

+        entry = rmm_malloc(client_rmm, sizeof(client_entry));

         if (!entry) {

             ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, APLOGNO(01767)

                          "unable to allocate new auth_digest client");