lib-index: Fix potential crash after resetting index

The log's sync_offset wasn't updated after the reset if there were no other
changes. This ended up in a broken state in
mail_transaction_log_append_locked() where it thought there was garbage at
the end of the transaction log, and crashed trying to truncate it.

diff --git a/src/lib-index/mail-index-transaction.c b/src/lib-index/mail-index-transaction.c
index d8245a3d9f6153bdc2c3ef3d4aef5ee3efe4b670..9a887d322066faeb0b5709341e9e344b301065c4 100644 (file)
--- a/src/lib-index/mail-index-transaction.c
+++ b/src/lib-index/mail-index-transaction.c
@@ -152,11 +152,6 @@ mail_transaction_log_file_refresh(struct mail_index_transaction *t,
                   transactions. */
                if (mail_transaction_log_rotate(t->view->index->log, TRUE) < 0)
                        return -1;
-
-               if (!MAIL_INDEX_TRANSACTION_HAS_CHANGES(t)) {
-                       /* we only wanted to reset */
-                       return 0;
-               }
        }
        file = t->view->index->log->head;
 
@@ -166,7 +161,7 @@ mail_transaction_log_file_refresh(struct mail_index_transaction *t,
 
        i_assert(file->sync_offset >= file->buffer_offset);
        ctx->new_highest_modseq = file->sync_highest_modseq;
-       return 1;
+       return 0;
 }
 
 static int
@@ -191,7 +186,7 @@ mail_index_transaction_commit_real(struct mail_index_transaction *t,
        if (mail_transaction_log_append_begin(log->index, trans_flags, &ctx) < 0)
                return -1;
        ret = mail_transaction_log_file_refresh(t, ctx);
-       if (ret > 0) T_BEGIN {
+       if (ret == 0) T_BEGIN {
                mail_index_transaction_finish(t);
                mail_index_transaction_export(t, ctx, changes_r);
        } T_END;