# HG changeset patch
# User Timo Sirainen <timo.sirainen@dovecot.fi>
# Date 1509987574 -7200
# Node ID 5524719c299ac5463da29b81e52eba25fe4b0604
# Parent  7fe2a998bc1ff7b0c761c38bca358c81633151c8
lib-storage: When copying mails, copy also empty cache fields

This mainly means that it copies cache fields for nonexistent message
headers. Those are still important, because otherwise Dovecot doesn't know
whether they exist or not.

diff -r 7fe2a998bc1f -r 5524719c299a src/lib-storage/index/index-storage.c
--- a/src/lib-storage/index/index-storage.c	Tue Nov 07 17:36:05 2017 +0200
+++ b/src/lib-storage/index/index-storage.c	Mon Nov 06 18:59:34 2017 +0200
@@ -935,6 +935,7 @@
 	const struct mail_cache_field *dest_field;
 	unsigned int src_field_idx, dest_field_idx;
 	uint32_t t;
+	bool add = FALSE;
 
 	src_field_idx = mail_cache_register_lookup(src_mail->box->cache, name);
 	i_assert(src_field_idx != UINT_MAX);
@@ -957,12 +958,14 @@
 		/* save date must update when mail is copied */
 		t = ioloop_time;
 		buffer_append(buf, &t, sizeof(t));
+		add = TRUE;
+	} else if (mail_cache_lookup_field(src_mail->transaction->cache_view, buf,
+					   src_mail->seq, src_field_idx) <= 0) {
+		/* error / not found */
+		buffer_set_used_size(buf, 0);
 	} else {
-		if (mail_cache_lookup_field(src_mail->transaction->cache_view, buf,
-					    src_mail->seq, src_field_idx) <= 0)
-			buffer_set_used_size(buf, 0);
-		else if (strcmp(name, "size.physical") == 0 ||
-			 strcmp(name, "size.virtual") == 0) {
+		if (strcmp(name, "size.physical") == 0 ||
+		    strcmp(name, "size.virtual") == 0) {
 			/* FIXME: until mail_cache_lookup() can read unwritten
 			   cached data from buffer, we'll do this optimization
 			   to make quota plugin's work faster */
@@ -977,8 +980,11 @@
 			else
 				imail->data.virtual_size = size;
 		}
+		/* NOTE: we'll want to add also nonexistent headers, which
+		   will keep the buf empty */
+		add = TRUE;
 	}
-	if (buf->used > 0) {
+	if (add) {
 		mail_cache_add(dest_trans->cache_trans, dest_seq,
 			       dest_field_idx, buf->data, buf->used);
 	}