lib-index: Automatically grow header size on header updates.

This fixes assert-crashes when it didn't happen.

For example an old Maildir index could have had a header size 24. Dovecot
crashed then when trying to update it, because the new header size is 36 and
there wasn't an explicit mail_index_ext_resize_hdr() call.

diff --git a/src/lib-index/mail-index-transaction-export.c b/src/lib-index/mail-index-transaction-export.c
index fd628eb3166eff9b08291401207d9583db4920ef..4b24471612de2fadc8de0a0e3fcec796fb682ac3 100644 (file)
--- a/src/lib-index/mail-index-transaction-export.c
+++ b/src/lib-index/mail-index-transaction-export.c
@@ -81,6 +81,18 @@ log_get_hdr_update_buffer(struct mail_index_transaction *t, bool prepend)
        return buf;
 }
 
+static unsigned int
+ext_hdr_update_get_size(const struct mail_index_transaction_ext_hdr_update *hu)
+{
+       unsigned int i;
+
+       for (i = hu->alloc_size; i > 0; i--) {
+               if (hu->mask[i-1] != 0)
+                       return i;
+       }
+       return 0;
+}
+
 static void log_append_ext_intro(struct mail_index_export_context *ctx,
                                 uint32_t ext_id, uint32_t reset_id,
                                 unsigned int *hdr_size_r)
@@ -139,6 +151,18 @@ static void log_append_ext_intro(struct mail_index_export_context *ctx,
                        intro->name_size = 0;
                }
                intro->flags = MAIL_TRANSACTION_EXT_INTRO_FLAG_NO_SHRINK;
+
+               /* handle increasing header size automatically */
+               if (array_is_created(&t->ext_hdr_updates) &&
+                   ext_id < array_count(&t->ext_hdr_updates)) {
+                       const struct mail_index_transaction_ext_hdr_update *hu;
+                       unsigned int hdr_update_size;
+
+                       hu = array_idx(&t->ext_hdr_updates, ext_id);
+                       hdr_update_size = ext_hdr_update_get_size(hu);
+                       if (intro->hdr_size < hdr_update_size)
+                               intro->hdr_size = hdr_update_size;
+               }
        }
        if (reset_id != 0) {
                /* we're going to reset this extension in this transaction */