diff --git a/g10/getkey.c b/g10/getkey.c
index 5e8c1c9f5..c0184c209 100644
--- a/g10/getkey.c
+++ b/g10/getkey.c
@@ -3035,27 +3035,35 @@ get_long_user_id_string( u32 *keyid )
 char*
 get_user_id( u32 *keyid, size_t *rn )
 {
-    user_id_db_t r;
-    char *p;
-    int pass=0;
+  user_id_db_t r;
+  char *p;
+  int pass = 0;
 
-    /* try it two times; second pass reads from key resources */
-    do {
-	for(r=user_id_db; r; r = r->next ) {
-            keyid_list_t a;
-            for (a=r->keyids; a; a= a->next ) {
-                if( a->keyid[0] == keyid[0] && a->keyid[1] == keyid[1] ) {
-                    p = xmalloc( r->len );
-                    memcpy(p, r->name, r->len );
-                    *rn = r->len;
-                    return p;
-                }
-            }
-        }
-    } while( ++pass < 2 && !get_pubkey( NULL, keyid ) );
-    p = xstrdup( user_id_not_found_utf8 () );
-    *rn = strlen(p);
-    return p;
+  /* Try it two times; second pass reads from key resources.  */
+  do
+    {
+      for (r = user_id_db; r; r = r->next)
+	{
+	  keyid_list_t a;
+	  for (a = r->keyids; a; a = a->next)
+	    {
+	      if (a->keyid[0] == keyid[0] && a->keyid[1] == keyid[1])
+		{
+                  /* An empty string as user id is possible.  Make
+                     sure that the malloc allocates one byte and does
+                     not bail out.  */
+		  p = xmalloc (r->len? r->len : 1);
+		  memcpy (p, r->name, r->len);
+		  *rn = r->len;
+		  return p;
+		}
+	    }
+	}
+    }
+  while (++pass < 2 && !get_pubkey (NULL, keyid));
+  p = xstrdup (user_id_not_found_utf8 ());
+  *rn = strlen (p);
+  return p;
 }
 
 char*
diff --git a/jnlib/xmalloc.c b/jnlib/xmalloc.c
index eb6d5ab11..244f7643e 100644
--- a/jnlib/xmalloc.c
+++ b/jnlib/xmalloc.c
@@ -36,7 +36,15 @@ out_of_core(void)
 void *
 xmalloc( size_t n )
 {
-    void *p = malloc( n );
+    void *p;
+
+    /* Make sure that xmalloc (0) works.  This is the same behaviour
+       has in gpg 2.x.  Note that in contrast to this code, Libgcrypt
+       (and thus most xmallocs in gpg 2.x) detect the !n and bail out.  */
+    if (!n)
+      n = 1;
+
+    p = malloc( n );
     if( !p )
 	out_of_core();
     return p;
@@ -54,7 +62,14 @@ xrealloc( void *a, size_t n )
 void *
 xcalloc( size_t n, size_t m )
 {
-    void *p = calloc( n, m );
+    void *p;
+
+    if (!n)
+      n = 1;
+    if (!m)
+      m = 1;
+
+    p = calloc( n, m );
     if( !p )
 	out_of_core();
     return p;