Provide a way to discern between erroneous return and user-induced break condition in foreach iterator functions

* libmailutils/diag/errors (MU_ERR_USER0-MU_ERR_USER7): New error constants.
Reserved for user's purposes, such as breaking from foreach iterators.
* libmaildutils/list/foreach.c (mu_list_foreach): Treat NULL list as a list
of 0 elements.
* libmailutils/list/foreachdir.c (mu_list_foreach_dir): Likewise.
* imap4d/imap4d.h (imap4d_auth_result): Remap constants to MU_ERR_USER[0-2]
* libmu_sieve/prog.c (mu_i_sv_lint_command): Use mu_list_locate with
the default comparator.
* mh/mh_list.c (_comp_name): Rewrite to match the definition of
mu_list_comparator_t
(mhl_format_run): Set _comp_name as comparator for the
env.printed_fields list.
(header_is_printed): Use mu_list_locate.

* imap4d/authenticate.c: Use MU_ERR_USER0-MU_ERR_USER7 to indicate
normal break condition in foreach iterators.
* imap4d/imap4d.c: Likewise.
* imap4d/namespace.c: Likewise.
* libmailutils/auth/auth.c: Likewise.
* libmailutils/cfg/driver.c: Likewise.
* libmailutils/cfg/parser.y: Likewise.
* libmailutils/server/acl.c: Likewise.
* libmailutils/server/msrv.c: Likewise.
* libmu_sieve/conf.c: Likewise.
* libmu_sieve/load.c: Likewise.
* libmu_sieve/sieve.l: Likewise.
* libmu_sieve/strexp.c: Likewise.
* libproto/imap/mbox.c: Likewise.
* libproto/imap/search.c: Likewise.
* mh/mh_format.c: Likewise.
* mh/send.c: Likewise.
* mh/sortm.c: Likewise.
* mimeview/mimetypes.y: Likewise.
* movemail/movemail.c: Likewise.

4 files changed, 25 insertions, 11 deletions

diff --git a/imap4d/authenticate.c b/imap4d/authenticate.c
index 92c4719d8..13fcf9a3e 100644
--- a/imap4d/authenticate.c
+++ b/imap4d/authenticate.c
@@ -96,7 +96,7 @@ imap4d_authenticate (struct imap4d_session *session,
 {
   char *auth_type;
   struct imap4d_auth adata;
-  enum imap4d_auth_result res;
+  int res;
   
   if (imap4d_tokbuf_argc (tok) != 3)
     return io_completion_response (command, RESP_BAD, "Invalid arguments");
@@ -136,6 +136,10 @@ imap4d_authenticate (struct imap4d_session *session,
     case imap4d_auth_fail:
       adata.response = RESP_NO;
       break;
+
+    default:
+      adata.response = RESP_NO;
+      mu_error ("%s", mu_strerror (res));
     }
   return io_completion_response (command, adata.response,
 				 "%s authentication failed", auth_type);
diff --git a/imap4d/imap4d.c b/imap4d/imap4d.c
index df9cc7a2b..348e615a0 100644
--- a/imap4d/imap4d.c
+++ b/imap4d/imap4d.c
@@ -340,11 +340,11 @@ check_user_groups (void *item, void *data)
     return 0;
 
   if (gp->gr_gid == auth_data->gid)
-    return MU_ERR_EXISTS;
+    return MU_ERR_USER0;
 
   for (p = gp->gr_mem; *p; p++)
     if (strcmp (*p, auth_data->name) == 0)
-      return MU_ERR_EXISTS;
+      return MU_ERR_USER0;
 
   return 0;
 }
@@ -353,7 +353,7 @@ static int
 imap_check_group_list (mu_list_t l)
 {
   int rc = mu_list_foreach (l, check_user_groups, NULL);
-  if (rc == MU_ERR_EXISTS) 
+  if (rc == MU_ERR_USER0) 
     return 0;
   else if (rc == 0)
     return MU_ERR_NOENT;
diff --git a/imap4d/imap4d.h b/imap4d/imap4d.h
index d5472873c..c08290d30 100644
--- a/imap4d/imap4d.h
+++ b/imap4d/imap4d.h
@@ -467,10 +467,10 @@ struct imap4d_auth
 
 enum imap4d_auth_result
   {
-    imap4d_auth_nosup,
-    imap4d_auth_ok,
-    imap4d_auth_resp,
-    imap4d_auth_fail
+    imap4d_auth_nosup = 0,
+    imap4d_auth_ok    = MU_ERR_USER0,
+    imap4d_auth_resp  = MU_ERR_USER1,
+    imap4d_auth_fail  = MU_ERR_USER2
   };
   
 typedef enum imap4d_auth_result
diff --git a/imap4d/namespace.c b/imap4d/namespace.c
index 9d694942c..e05aa132e 100644
--- a/imap4d/namespace.c
+++ b/imap4d/namespace.c
@@ -83,8 +83,18 @@ namespace_enumerate (int id, nsfp_t f, void *closure)
   nsc.id = id;
   nsc.fun = f;
   nsc.closure = closure;
-  return namespace[id] == 0 ? 0 :
-          mu_list_foreach (namespace[id], _enum_fun, &nsc);
+  if (namespace[id])
+    {
+      int rc = mu_list_foreach (namespace[id], _enum_fun, &nsc);
+      if (rc == MU_ERR_USER0)
+	return 1;
+      else if (rc != 0)
+	{
+	  mu_diag_funcall (MU_DIAG_ERROR, "mu_list_foreach", NULL, rc);
+	  return 0;
+	}
+    }
+  return 0;
 }
 
 static int
@@ -149,7 +159,7 @@ check_namespace (void *closure, int ns, char *path, int delim)
     {
       p->ns = ns;
       p->exact = len == p->namelen;
-      return 1;
+      return MU_ERR_USER0;
     }
   return 0;
 }