message: support 'personal' flag for messages

Add a new flag 'personal' for a message, which means that at least one of the
contact fields is personal.

lib/message/mu-flags.cc

@@ -166,7 +166,7 @@ test_flag_info()
 {
 	static_assert(flag_info('D')->flag == Flags::Draft);
 	static_assert(flag_info('l')->flag == Flags::MailingList);
-	static_assert(!flag_info('q'));
+	static_assert(!flag_info('y'));
 
 	static_assert(flag_info("trashed")->flag == Flags::Trashed);
 	static_assert(flag_info("attach")->flag == Flags::HasAttachment);

lib/message/mu-flags.hh

@@ -63,11 +63,12 @@ enum struct Flags {
 	 * other content flags
 	 */
 	MailingList = 1 << 11, /**< A mailing-list message */
-
+	Personal    = 1 << 12, /**< A personal message (i.e., at least one of the
+				* contact fields contains a personal address) */
 	/*
 	 * <private>
 	 */
-	_final_ = 1 << 12
+	_final_ = 1 << 13
 };
 MU_ENABLE_BITOPS(Flags);
 
@@ -90,7 +91,9 @@ enum struct MessageFlagCategory {
 struct MessageFlagInfo {
 
 	Flags			flag;		/**< The message flag */
-	char			shortcut;	/**< Shortcut character */
+	char			shortcut;	/**< Shortcut character;
+						 * tolower(shortcut) must be
+						 * unique for all flags */
 	std::string_view	name;		/**< Name of the flag */
 	MessageFlagCategory	category;	/**< Flag category */
 	std::string_view        description;    /**< Description */
@@ -109,7 +112,7 @@ struct MessageFlagInfo {
 /**
  * Array of all flag information.
  */
-constexpr std::array<MessageFlagInfo, 12> AllMessageFlagInfos = {{
+constexpr std::array<MessageFlagInfo, 13> AllMessageFlagInfos = {{
     MessageFlagInfo{Flags::Draft,        'D', "draft",		MessageFlagCategory::Mailfile,
 	    "Draft (in progress)"
     },
@@ -147,6 +150,9 @@ constexpr std::array<MessageFlagInfo, 12> AllMessageFlagInfos = {{
     MessageFlagInfo{Flags::MailingList,	 'l', "list",		MessageFlagCategory::Content,
 	    "Mailing list message"
     },
+    MessageFlagInfo{Flags::Personal,	 'q', "personal",	MessageFlagCategory::Content,
+	    "Personal message"
+    },
 }};
 
 

lib/mu-contacts-cache.cc

@@ -221,9 +221,9 @@ ContactsCache::add(Contact&& contact)
 
 
 void
-ContactsCache::add(Contacts&& contacts)
+ContactsCache::add(Contacts&& contacts, bool& personal)
 {
-	const auto personal = seq_find_if(contacts,[&](auto&& c){
+	personal = seq_find_if(contacts,[&](auto&& c){
 		return is_personal(c.email); }) != contacts.cend();
 
 	for (auto&& contact: contacts) {

lib/mu-contacts-cache.hh

@@ -66,8 +66,15 @@ public:
 	 * any of the senders/recipients are considered "personal"
 	 *
 	 * @param contacts a Contact object sequence
+	 * @param is_personal receives true if any of the contacts was personal;
+	 * false otherwise
 	 */
-	void add(Contacts&& contacts);
+	void add(Contacts&& contacts, bool& is_personal);
+	void add(Contacts&& contacts) {
+		bool _ignore;
+		add(std::move(contacts), _ignore);
+	}
+
 
 	/**
 	 * Clear all contacts

lib/mu-store.cc

@@ -344,14 +344,24 @@ Store::add_message(Message& msg, bool use_transaction)
 
 	if (auto&& res = msg.set_maildir(mdir.value()); !res)
 		return Err(res.error());
+	/* add contacts from this message to cache; this cache
+	 * also determines whether those contacts are _personal_, i.e. match
+	 * our personal addresses.
+	 *
+	 * if a message has any personal contacts, mark it as personal; do
+	 * this by updating the message flags.
+	 */
+	bool is_personal{};
+	priv_->contacts_cache_.add(msg.all_contacts(), is_personal);
+	if (is_personal)
+		msg.set_flags(msg.flags() | Flags::Personal);
+
 	/* now, we're done with all the fields; generate the sexp string for this
 	 * message */
 	msg.update_cached_sexp();
 
 	std::lock_guard guard{priv_->lock_};
 
-	priv_->contacts_cache_.add(msg.all_contacts());
-
 	const auto docid = xapian_try([&]{
 
 		if (use_transaction)