From: Timo Sirainen <timo.sirainen@dovecot.fi>
Date: Thu, 6 Jul 2017 08:24:35 +0000 (+0300)
Subject: virtual: Avoid assert-crash if backend mailbox's have_guid lookup fails
X-Git-Tag: 2.3.0.rc1~1312
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=d5282594ec73c953ffb23096a2cddf373cc15f46;p=thirdparty%2Fdovecot%2Fcore.git

virtual: Avoid assert-crash if backend mailbox's have_guid lookup fails

The MAIL_ERROR_NOTFOUND can happen if the mailbox was already deleted.
Other errors aren't expected to happen and possibly point to a bug.

Fixes:
Panic: file mail-storage.c: line 1831: unreached
---

diff --git a/src/plugins/virtual/virtual-storage.c b/src/plugins/virtual/virtual-storage.c
index 32b89ba7de..2066ea81be 100644
--- a/src/plugins/virtual/virtual-storage.c
+++ b/src/plugins/virtual/virtual-storage.c
@@ -554,8 +554,23 @@ static int virtual_storage_set_have_guid_flags(struct virtual_mailbox *mbox)
 	bboxes = array_get(&mbox->backend_boxes, &count);
 	for (i = 0; i < count; i++) {
 		if (mailbox_get_status(bboxes[i]->box, 0, &status) < 0) {
-			virtual_box_copy_error(&mbox->box, bboxes[i]->box);
-			return -1;
+			const char *errstr;
+			enum mail_error error;
+
+			errstr = mailbox_get_last_error(bboxes[i]->box, &error);
+			if (error == MAIL_ERROR_NOTFOUND) {
+				/* backend mailbox was just lost - skip it */
+				continue;
+			}
+			/* Not expected to happen, but we can't return failure
+			   since this could be called from
+			   mailbox_get_open_status() and it would panic.
+			   So just log the error and skip the mailbox. */
+			mail_storage_set_critical(mbox->box.storage,
+				"Virtual mailbox %s: Failed to get have_guid existence for backend mailbox %s: %s",
+				mailbox_get_vname(&mbox->box),
+				mailbox_get_vname(bboxes[i]->box), errstr);
+			continue;
 		}
 		if (!status.have_guids)
 			mbox->have_guids = FALSE;