[evolution-data-server] Deadlock when marking as read message in a search folder

[Milan Crha <mcrha src gnome org>]

commit fd0753b23de7e0e4c8a7731a21aa20b09924ab7f
Author: Milan Crha <mcrha redhat com>
Date:   Mon Nov 19 14:03:47 2018 +0100

    Deadlock when marking as read message in a search folder
    
    There could happen a deadlock when two threads change for example
    message info flags, where one threads holds message info's summary lock
    and is waiting for the info's property lock, which the other thread
    hold's info's property lock and is waiting for the summary lock.
    It's safer to hold summary lock before acquiring the message info's
    lock when anything will be changed in the message info, which didn't
    happen here.
    
    This had been reported downstream at:
    https://bugzilla.redhat.com/show_bug.cgi?id=1649373

 src/camel/camel-folder.c     | 44 +++++++++++++++++++++++++++++++++++++++-----
 src/camel/camel-vee-folder.c |  4 ++++
 2 files changed, 43 insertions(+), 5 deletions(-)
---
diff --git a/src/camel/camel-folder.c b/src/camel/camel-folder.c
index abece0c9f..c017bc365 100644
--- a/src/camel/camel-folder.c
+++ b/src/camel/camel-folder.c
@@ -285,25 +285,41 @@ folder_filter (CamelSession *session,
 
        /* Reset junk learn flag so that we don't process it again */
        if (data->junk) {
+               CamelFolderSummary *summary;
+
+               summary = camel_folder_get_folder_summary (data->folder);
+
+               camel_folder_summary_lock (summary);
+
                for (i = 0; i < data->junk->len; i++) {
-                       info = camel_folder_summary_get (camel_folder_get_folder_summary (data->folder), 
data->junk->pdata[i]);
+                       info = camel_folder_summary_get (summary, data->junk->pdata[i]);
                        if (!info)
                                continue;
 
                        camel_message_info_set_flags (info, CAMEL_MESSAGE_JUNK_LEARN, 0);
                        g_clear_object (&info);
                }
+
+               camel_folder_summary_unlock (summary);
        }
 
        if (data->notjunk) {
+               CamelFolderSummary *summary;
+
+               summary = camel_folder_get_folder_summary (data->folder);
+
+               camel_folder_summary_lock (summary);
+
                for (i = 0; i < data->notjunk->len; i++) {
-                       info = camel_folder_summary_get (camel_folder_get_folder_summary (data->folder), 
data->notjunk->pdata[i]);
+                       info = camel_folder_summary_get (summary, data->notjunk->pdata[i]);
                        if (!info)
                                continue;
 
                        camel_message_info_set_flags (info, CAMEL_MESSAGE_JUNK_LEARN, 0);
                        g_clear_object (&info);
                }
+
+               camel_folder_summary_unlock (summary);
        }
 
        if (data->junk) {
@@ -749,13 +765,19 @@ folder_set_message_flags (CamelFolder *folder,
 
        g_return_val_if_fail (folder->priv->summary != NULL, FALSE);
 
+       camel_folder_summary_lock (folder->priv->summary);
+
        info = camel_folder_summary_get (folder->priv->summary, uid);
-       if (info == NULL)
+       if (info == NULL) {
+               camel_folder_summary_unlock (folder->priv->summary);
                return FALSE;
+       }
 
        res = camel_message_info_set_flags (info, mask, set);
        g_clear_object (&info);
 
+       camel_folder_summary_unlock (folder->priv->summary);
+
        return res;
 }
 
@@ -789,12 +811,18 @@ folder_set_message_user_flag (CamelFolder *folder,
 
        g_return_if_fail (folder->priv->summary != NULL);
 
+       camel_folder_summary_lock (folder->priv->summary);
+
        info = camel_folder_summary_get (folder->priv->summary, uid);
-       if (info == NULL)
+       if (info == NULL) {
+               camel_folder_summary_unlock (folder->priv->summary);
                return;
+       }
 
        camel_message_info_set_user_flag (info, name, value);
        g_clear_object (&info);
+
+       camel_folder_summary_unlock (folder->priv->summary);
 }
 
 static const gchar *
@@ -827,12 +855,18 @@ folder_set_message_user_tag (CamelFolder *folder,
 
        g_return_if_fail (folder->priv->summary != NULL);
 
+       camel_folder_summary_lock (folder->priv->summary);
+
        info = camel_folder_summary_get (folder->priv->summary, uid);
-       if (info == NULL)
+       if (info == NULL) {
+               camel_folder_summary_unlock (folder->priv->summary);
                return;
+       }
 
        camel_message_info_set_user_tag (info, name, value);
        g_clear_object (&info);
+
+       camel_folder_summary_unlock (folder->priv->summary);
 }
 
 static GPtrArray *
diff --git a/src/camel/camel-vee-folder.c b/src/camel/camel-vee-folder.c
index aae394c7c..383e92385 100644
--- a/src/camel/camel-vee-folder.c
+++ b/src/camel/camel-vee-folder.c
@@ -139,6 +139,8 @@ vee_folder_note_added_uid (CamelVeeFolder *vfolder,
 {
        const gchar *vuid;
 
+       camel_folder_summary_lock (CAMEL_FOLDER_SUMMARY (vsummary));
+
        vuid = camel_vee_message_info_data_get_vee_message_uid (added_mi_data);
        if (!camel_folder_summary_check_uid (CAMEL_FOLDER_SUMMARY (vsummary), vuid)) {
                /* add it only if it wasn't in yet */
@@ -158,6 +160,8 @@ vee_folder_note_added_uid (CamelVeeFolder *vfolder,
                if (included_as_changed && changes)
                        camel_folder_change_info_change_uid (changes, vuid);
        }
+
+       camel_folder_summary_unlock (CAMEL_FOLDER_SUMMARY (vsummary));
 }
 
 static void