kfileitemmodelrolesupdater: fix directory item count for large folders

Dolphin reported an incorrect item count in the "Size" column for directories containing 200 or more entries.

Use KIO::ListJob::ListFlag::ExcludeDotAndDotDot and ExcludeHidden to filter entries at the source.

Use a local counter (totalCount) captured via std::shared_ptr in the lambda to ensure each scan job starts from zero and maintains its own state.

Add a fast path using list.size() when showDirectoriesOnly is false to improve performance.

BUG: 509150

1 files changed, 25 insertions, 21 deletions

diff --git a/src/kitemviews/kfileitemmodelrolesupdater.cpp b/src/kitemviews/kfileitemmodelrolesupdater.cpp
index 0f4816424..38fa58436 100644
--- a/src/kitemviews/kfileitemmodelrolesupdater.cpp
+++ b/src/kitemviews/kfileitemmodelrolesupdater.cpp
@@ -1288,36 +1288,40 @@ void KFileItemModelRolesUpdater::startDirectorySizeCounting(const KFileItem &ite
         m_model->setData(index, data);
         connect(m_model, &KFileItemModel::itemsChanged, this, &KFileItemModelRolesUpdater::slotItemsChanged);
 
-        auto listJob = KIO::listDir(url, KIO::HideProgressInfo);
+        // Use KIO flags to exclude dot entries at the source to simplify counting
+        KIO::ListJob::ListFlags flags = KIO::ListJob::ListFlag::ExcludeDotAndDotDot;
+        if (!m_model->showHiddenFiles()) {
+            flags |= KIO::ListJob::ListFlag::ExcludeHidden;
+        }
+
+        auto listJob = KIO::listDir(url, KIO::HideProgressInfo, flags);
 
-        QObject::connect(listJob, &KIO::ListJob::entries, this, [this, item](const KJob *job, const KIO::UDSEntryList &list) {
+        // Define a local counter to accumulate results for THIS specific job instance.
+        // Using a shared pointer allows the lambda batches to share and update the same state.
+        auto totalCount = std::make_shared<int>(0);
+
+        QObject::connect(listJob, &KIO::ListJob::entries, this, [this, item, totalCount](const KJob *job, const KIO::UDSEntryList &list) {
+            Q_UNUSED(job)
             int index = m_model->index(item);
             if (index < 0) {
                 return;
             }
-            auto data = m_model->data(index);
-            int origCount = data.value("count").toInt();
-            // Get the amount of processed items...
-            int entryCount = job->processedAmount(KJob::Bytes);
-
-            // ...and then remove the unwanted items from the amount.
-            for (const KIO::UDSEntry &entry : list) {
-                const auto name = entry.stringValue(KIO::UDSEntry::UDS_NAME);
 
-                if (name == QStringLiteral("..") || name == QStringLiteral(".")) {
-                    --entryCount;
-                    continue;
-                }
-                if (!m_model->showHiddenFiles() && name.startsWith(QLatin1Char('.'))) {
-                    --entryCount;
-                    continue;
-                }
-                if (m_model->showDirectoriesOnly() && !entry.isDir()) {
-                    --entryCount;
-                    continue;
+            // Accumulate entries for this batch into our job-specific counter
+            if (!m_model->showDirectoriesOnly()) {
+                *totalCount += list.size();
+            } else {
+                for (const KIO::UDSEntry &entry : list) {
+                    if (entry.isDir()) {
+                        (*totalCount)++;
+                    }
                 }
             }
 
+            const int entryCount = *totalCount;
+            auto data = m_model->data(index);
+            int origCount = data.value("count").toInt();
+
             QHash<QByteArray, QVariant> newData;
             QVariant expandable = data.value("isExpandable");
             if (expandable.isNull() || expandable.toBool() != (entryCount > 0)) {