fix(startup): let startup_query name a built-in filter, and run it

Two defects, both reachable only after item 93.

startupSavedQuery() searched the saved queries alone, so a startup_query of
"Inbox" matched nothing once Inbox shipped as a built-in filter and the
duplicated entry was removed from queries.json. It then fell back to
m_savedQueries.first(), which is an arbitrary choice that used to look
reasonable while every install carried an Inbox entry: with the duplicates gone
it opened on a leftover search for one sender, and an empty queries.json opened
on nothing at all. The search now covers the saved queries first, so the user's
own entry wins a name collision, then the built-in filters; the fallback is the
Unread filter, which is always present.

The default startup name has always been "Unread" and now resolves for the
first time: before this it named nothing unless the user happened to have such
an entry.

The constructor also read startup.query directly, and a generated entry stores
no query at all, so even a matching filter opened an empty bar. It resolves
through Config::resolvedQuery() now, unscoped, since the account dropdown
starts on "All accounts".

Icons per the user's choices: a star for Important rather than the flag
action's own icon, since on the query row an icon reads as a category rather
than as an instruction, and mail-folder-sent rather than mail-sent.

Three tests changed rather than adapted, because their premises were the
defect. Two asserted the first-saved-query fallback.
aCronSyncDoesNotRefreshBeforeAnyQueryHasRun assumed a fresh window had run no
query, which is no longer true; it is now
aCronSyncRefreshesTheLastRunQueryNotTheQueryBar and asserts the property that
actually matters on a cron timer, through a new lastRunQueryForTesting() seam,
since a legitimate refresh bumps the generation and the counter cannot tell the
two apart.

1 files changed, 20 insertions, 7 deletions

diff --git a/src/config.cpp b/src/config.cpp
index 0b7fe86..8ca7910 100644
--- a/src/config.cpp
+++ b/src/config.cpp
@@ -784,18 +784,31 @@ QString Config::resolvedQuery(const SavedQuery &query,
 
 SavedQuery Config::startupSavedQuery() const
 {
-    if (m_savedQueries.isEmpty())
-        return {};
-
+    // The user's own queries first, so a saved query wins a name collision with
+    // a built-in filter: they named theirs deliberately, where the filter's
+    // name is one this application chose for them.
     for (const SavedQuery &query : m_savedQueries) {
         if (query.name.compare(m_startupQuery, Qt::CaseInsensitive) == 0)
             return query;
     }
 
-    // Named a query that does not exist. Not worth a warning: the default is
-    // a name the user never wrote, so an install with no [queries] Unread
-    // entry would warn on every launch about a key it never set.
-    return m_savedQueries.first();
+    // Then the built-in filters. Without this, a startup_query of "Inbox"
+    // matched nothing once item 93 shipped Inbox as a filter and the duplicated
+    // saved query was removed, and the app started on whatever query happened
+    // to be first in the file.
+    for (const SavedQuery &filter : builtinFilters()) {
+        if (filter.name.compare(m_startupQuery, Qt::CaseInsensitive) == 0)
+            return filter;
+    }
+
+    // Named nothing that exists. Falling back to m_savedQueries.first() is what
+    // this used to do and it is worse than it looks: after the duplicated
+    // entries were removed it could be any leftover query, so a startup view
+    // became a search for one sender, and an empty queries.json started nothing
+    // at all. A filter is always present, so the fallback can be one.
+    //
+    // Still not worth a warning: the default is a name the user never wrote.
+    return builtinFilter(QStringLiteral("unread"));
 }
 
 Account Config::account(const QString &key) const