[evolution-data-server] I#14 - [IMAPx] Use extended LIST with Cyrus IMAP >= 2.5.11

[Milan Crha <mcrha src gnome org>]

commit 3943f26b604cc3145950fef2b664b7d8823dd3c6
Author: Milan Crha <mcrha redhat com>
Date:   Mon Jul 2 10:24:08 2018 +0200

    I#14 - [IMAPx] Use extended LIST with Cyrus IMAP >= 2.5.11
    
    Closes https://gitlab.gnome.org/GNOME/evolution-data-server/issues/14

 src/camel/providers/imapx/camel-imapx-server.c | 61 ++++++++++++++++++++++----
 1 file changed, 52 insertions(+), 9 deletions(-)
---
diff --git a/src/camel/providers/imapx/camel-imapx-server.c b/src/camel/providers/imapx/camel-imapx-server.c
index af3d6147e..dda59f1ed 100644
--- a/src/camel/providers/imapx/camel-imapx-server.c
+++ b/src/camel/providers/imapx/camel-imapx-server.c
@@ -291,7 +291,7 @@ struct _CamelIMAPXServerPrivate {
        GCancellable *idle_cancellable;
        guint idle_stamp;
 
-       gboolean is_cyrus;
+       gboolean is_broken_cyrus;
 
        /* Info about the current connection; guarded by priv->stream_lock */
        struct _capability_info *cinfo;
@@ -619,7 +619,7 @@ imapx_server_stash_command_arguments (CamelIMAPXServer *is)
        is->priv->status_data_items = g_string_free (buffer, FALSE);
 
        g_free (is->priv->list_return_opts);
-       if (!is->priv->is_cyrus && CAMEL_IMAPX_HAVE_CAPABILITY (is->priv->cinfo, LIST_EXTENDED)) {
+       if (!is->priv->is_broken_cyrus && CAMEL_IMAPX_HAVE_CAPABILITY (is->priv->cinfo, LIST_EXTENDED)) {
                buffer = g_string_new ("CHILDREN SUBSCRIBED");
                if (CAMEL_IMAPX_HAVE_CAPABILITY (is->priv->cinfo, LIST_STATUS))
                        g_string_append_printf (
@@ -1858,6 +1858,49 @@ imapx_untagged_preauth (CamelIMAPXServer *is,
        return TRUE;
 }
 
+static gboolean
+imapx_server_check_is_good_cyrus (const gchar *response_text)
+{
+       const gchar *pp;
+       gint vermajor = 0, verminor = 0, vermicro = 0;
+
+       if (!response_text || !*response_text)
+               return FALSE;
+
+       /* Expects "Cyrus IMAP v1.2.3", eventually "Cyrus IMAP 4.5.6" (with or without 'v' prefix) */
+       pp = camel_strstrcase (response_text, "cyrus");
+       if (!pp)
+               return FALSE;
+
+       #define skip_word() \
+               while (*pp && *pp != ' ') {     \
+                       pp++;                   \
+               }                               \
+                                               \
+               if (!*pp)                       \
+                       return FALSE;           \
+                                               \
+               pp++;
+
+       /* Skip the 'Cyrus' word */
+       skip_word ();
+
+       /* Skip the 'IMAP' word */
+       skip_word ();
+
+       #undef skip_word
+
+       /* Now is at version with or without 'v' prefix */
+       if (*pp == 'v')
+               pp++;
+
+       if (sscanf (pp, "%d.%d.%d", &vermajor, &verminor, &vermicro) != 3)
+               return FALSE;
+
+       /* The 2.5.11, inclusive, has the issue fixed, thus check for that version. */
+       return vermajor > 2 || (vermajor == 2 && (verminor > 5 || (verminor == 5 && vermicro >= 11)));
+}
+
 static gboolean
 imapx_untagged_ok_no_bad (CamelIMAPXServer *is,
                           GInputStream *input_stream,
@@ -1987,8 +2030,8 @@ imapx_untagged_ok_no_bad (CamelIMAPXServer *is,
                        if (is->priv->context->sinfo->text) {
                                guint32 list_extended = imapx_lookup_capability ("LIST-EXTENDED");
 
-                               is->priv->is_cyrus = is->priv->is_cyrus || camel_strstrcase 
(is->priv->context->sinfo->text, "cyrus");
-                               if (is->priv->is_cyrus && is->priv->cinfo && (is->priv->cinfo->capa & 
list_extended) != 0) {
+                               is->priv->is_broken_cyrus = is->priv->is_broken_cyrus || 
!imapx_server_check_is_good_cyrus (is->priv->context->sinfo->text);
+                               if (is->priv->is_broken_cyrus && is->priv->cinfo && (is->priv->cinfo->capa & 
list_extended) != 0) {
                                        /* Disable LIST-EXTENDED for cyrus servers */
                                        c (is->priv->tagprefix, "Disabling LIST-EXTENDED extension for a 
Cyrus server\n");
                                        is->priv->cinfo->capa &= ~list_extended;
@@ -2448,8 +2491,8 @@ imapx_completion (CamelIMAPXServer *is,
        if (ic->status->condition == IMAPX_CAPABILITY) {
                guint32 list_extended = imapx_lookup_capability ("LIST-EXTENDED");
 
-               is->priv->is_cyrus = is->priv->is_cyrus || (ic->status->text && camel_strstrcase 
(ic->status->text, "cyrus"));
-               if (is->priv->is_cyrus && ic->status->u.cinfo && (ic->status->u.cinfo->capa & list_extended) 
!= 0) {
+               is->priv->is_broken_cyrus = is->priv->is_broken_cyrus || (ic->status->text && 
!imapx_server_check_is_good_cyrus (ic->status->text));
+               if (is->priv->is_broken_cyrus && ic->status->u.cinfo && (ic->status->u.cinfo->capa & 
list_extended) != 0) {
                        /* Disable LIST-EXTENDED for cyrus servers */
                        c (is->priv->tagprefix, "Disabling LIST-EXTENDED extension for a Cyrus server\n");
                        ic->status->u.cinfo->capa &= ~list_extended;
@@ -3546,7 +3589,7 @@ camel_imapx_server_init (CamelIMAPXServer *is)
        is->priv->cancellable = g_cancellable_new ();
 
        is->priv->state = IMAPX_DISCONNECTED;
-       is->priv->is_cyrus = FALSE;
+       is->priv->is_broken_cyrus = FALSE;
        is->priv->copyuid_status = NULL;
 
        is->priv->changes = camel_folder_change_info_new ();
@@ -4028,7 +4071,7 @@ imapx_disconnect (CamelIMAPXServer *is)
        g_weak_ref_set (&is->priv->select_pending, NULL);
        g_mutex_unlock (&is->priv->select_lock);
 
-       is->priv->is_cyrus = FALSE;
+       is->priv->is_broken_cyrus = FALSE;
        is->priv->state = IMAPX_DISCONNECTED;
 
        g_mutex_lock (&is->priv->idle_lock);
@@ -4056,7 +4099,7 @@ camel_imapx_server_connect_sync (CamelIMAPXServer *is,
        if (is->priv->state >= IMAPX_INITIALISED)
                return TRUE;
 
-       is->priv->is_cyrus = FALSE;
+       is->priv->is_broken_cyrus = FALSE;
 
        if (!imapx_reconnect (is, cancellable, error))
                return FALSE;