Kill any running preview jobs before starting a new one

If loading a preview takes long, it was possible before this commit
that a preview for a new item was requested before the first preview
was shown. In that case, there was a race condition, and the first
preview to arrive stayed in the Information Panel.

This commit fixes this by keeping a pointer to the preview job and
killing it before starting a new one.

BUG: 250787
FIXED-IN: 4.12.1
REVIEW: 114561

1 files changed, 7 insertions, 1 deletions

diff --git a/src/panels/information/informationpanelcontent.h b/src/panels/information/informationpanelcontent.h
index ed9200aef..cad6b51b0 100644
--- a/src/panels/information/informationpanelcontent.h
+++ b/src/panels/information/informationpanelcontent.h
@@ -26,6 +26,8 @@
 #include <KUrl>
 #include <KVBox>
 
+#include <QPointer>
+
 class KFileItemList;
 class PhononWidget;
 class PixmapViewer;
@@ -35,6 +37,10 @@ class QString;
 class QLabel;
 class QScrollArea;
 
+namespace KIO {
+    class PreviewJob;
+}
+
 #ifndef HAVE_NEPOMUK
 class KFileMetaDataWidget;
 #else
@@ -135,7 +141,7 @@ private:
 private:
     KFileItem m_item;
 
-    bool m_pendingPreview;
+    QPointer<KIO::PreviewJob> m_previewJob;
     QTimer* m_outdatedPreviewTimer;
 
     PixmapViewer* m_preview;