imapc: Fix crashing when copying nonexistent mails

Check the msgmap before attempting to copy an mail which may has been
expunged already. Fixes:

Panic: file mail-storage.c: line 2385 (mailbox_transaction_commit_get_changes): assertion failed: (ret < 0 || seq_range_count(&changes_r->saved_uids) == save_count || array_count(&changes_r->saved_uids) == 0)

diff --git a/src/lib-storage/index/imapc/imapc-save.c b/src/lib-storage/index/imapc/imapc-save.c
index 63ed39cb9160d42cad66ae5007c24acac31719ae..4d15b0cdcd097a1ccbd0df603cfcee7ffb0e02db 100644 (file)
--- a/src/lib-storage/index/imapc/imapc-save.c
+++ b/src/lib-storage/index/imapc/imapc-save.c
@@ -10,6 +10,7 @@
 #include "index-mail.h"
 #include "mail-copy.h"
 #include "mailbox-list-private.h"
+#include "imapc-msgmap.h"
 #include "imapc-storage.h"
 #include "imapc-sync.h"
 #include "imapc-mail.h"
@@ -403,14 +404,29 @@ int imapc_copy(struct mail_save_context *_ctx, struct mail *mail)
 {
        struct imapc_save_context *ctx = IMAPC_SAVECTX(_ctx);
        struct mailbox_transaction_context *_t = _ctx->transaction;
-       struct imapc_mailbox *src_mbox = IMAPC_MAILBOX(mail->box);
+       struct imapc_mailbox *src_mbox;
+       struct imapc_msgmap *src_msgmap;
        struct imapc_command *cmd;
        struct imapc_save_cmd_context sctx;
+       uint32_t rseq;
 
        i_assert((_t->flags & MAILBOX_TRANSACTION_FLAG_EXTERNAL) != 0);
 
        if (_t->box->storage == mail->box->storage) {
+               src_mbox = IMAPC_MAILBOX(mail->box);
                /* same server, we can use COPY for the mail */
+               src_msgmap =
+                       imapc_client_mailbox_get_msgmap(src_mbox->client_box);
+               if (mail->expunged ||
+                   !imapc_msgmap_uid_to_rseq(src_msgmap, mail->uid, &rseq)) {
+                       mail_storage_set_error(mail->box->storage,
+                                              MAIL_ERROR_EXPUNGED,
+                                              "Some of the requested messages no longer exist.");
+                       ctx->finished = TRUE;
+                       index_save_context_free(_ctx);
+                       return -1;
+               }
+               /* Mail has not been expunged and can be copied. */
                sctx.ret = -2;
                sctx.ctx = ctx;
                cmd = imapc_client_mailbox_cmd(src_mbox->client_box,