Don't use mixed units in size-column of details-view

This makes it tricky to compare the filesizes without adjusting
the sort-order, so now all sizes in the size-column are shown
in KiB or KB (dependent on the KLocale setting).

BUG: 219932
FIXED-IN: 4.8.0

Related fixes:
- Stay consistent with the rounding when using the KiB/KB unit
  in the statusbar.
- Fix sorting-by-size issue for folders
- Show "Unknown" in the size-column when the number of items
  cannot be determined.

2 files changed, 24 insertions, 9 deletions

diff --git a/src/kitemviews/kfileitemlistwidget.cpp b/src/kitemviews/kfileitemlistwidget.cpp
index 5f659a1f6..d6b892658 100644
--- a/src/kitemviews/kfileitemlistwidget.cpp
+++ b/src/kitemviews/kfileitemlistwidget.cpp
@@ -192,13 +192,18 @@ QString KFileItemListWidget::roleText(const QByteArray& role, const QHash<QByteA
         if (values.value("isDir").toBool()) {
             // The item represents a directory. Show the number of sub directories
             // instead of the file size of the directory.
-            if (!roleValue.isNull()) {
+            if (roleValue.isNull()) {
+                text = i18nc("@item:intable", "Unknown");
+            } else {
                 const KIO::filesize_t size = roleValue.value<KIO::filesize_t>();
                 text = i18ncp("@item:intable", "%1 item", "%1 items", size);
             }
         } else {
-            const KIO::filesize_t size = roleValue.value<KIO::filesize_t>();
-            text = KIO::convertSize(size);
+            // Show the size in kilobytes (always round up)
+            const KLocale* locale = KGlobal::locale();
+            const int roundInc = (locale->binaryUnitDialect() == KLocale::MetricBinaryDialect) ? 499 : 511;
+            const KIO::filesize_t size = roleValue.value<KIO::filesize_t>() + roundInc;
+            text = locale->formatByteSize(size, 0, KLocale::DefaultBinaryDialect, KLocale::UnitKiloByte);
         }
         break;
     }
diff --git a/src/kitemviews/kfileitemmodel.cpp b/src/kitemviews/kfileitemmodel.cpp
index 4b026fea3..afc6decee 100644
--- a/src/kitemviews/kfileitemmodel.cpp
+++ b/src/kitemviews/kfileitemmodel.cpp
@@ -1032,12 +1032,22 @@ bool KFileItemModel::lessThan(const ItemData* a, const ItemData* b) const
     }
 
     case SizeRole: {
-        const KIO::filesize_t sizeA = itemA.size();
-        const KIO::filesize_t sizeB = itemB.size();
-        if (sizeA < sizeB) {
-            result = -1;
-        } else if (sizeA > sizeB) {
-            result = +1;
+        if (itemA.isDir()) {
+            Q_ASSERT(itemB.isDir()); // see "if (m_sortFoldersFirst || m_sortRole == SizeRole)" above
+
+            const QVariant valueA = a->values.value("size");
+            const QVariant valueB = b->values.value("size");
+
+            if (valueA.isNull()) {
+                result = -1;
+            } else if (valueB.isNull()) {
+                result = +1;
+            } else {
+                result = valueA.value<KIO::filesize_t>() - valueB.value<KIO::filesize_t>();
+            }
+        } else {
+            Q_ASSERT(!itemB.isDir()); // see "if (m_sortFoldersFirst || m_sortRole == SizeRole)" above
+            result = itemA.size() - itemB.size();
         }
         break;
     }