diff --git a/rtgui/filebrowser.cc b/rtgui/filebrowser.cc
index 7a32cd6b7..4326c1666 100644
--- a/rtgui/filebrowser.cc
+++ b/rtgui/filebrowser.cc
@@ -1496,7 +1496,7 @@ bool FileBrowser::checkFilter (ThumbBrowserEntryBase* entryb) const   // true ->
 
         for (const auto& entry : filter.vFilterStrings) {
             if (FileName.find(entry) != std::string::npos) {
-                iFilenameMatch++;
+                ++iFilenameMatch;
                 break;
             }
         }
diff --git a/rtgui/filebrowserentry.cc b/rtgui/filebrowserentry.cc
index 4b1764824..8b518335c 100644
--- a/rtgui/filebrowserentry.cc
+++ b/rtgui/filebrowserentry.cc
@@ -251,32 +251,32 @@ void FileBrowserEntry::_updateImage(rtengine::IImage8* img, double s, const rten
     bool newLandscape = img->getWidth() > img->getHeight();
     bool rotated = false;
 
-    if (preh == img->getHeight ()) {
+    if (preh == img->getHeight()) {
+        const bool resize = !preview || prew != img->getWidth();
         prew = img->getWidth ();
 
         GThreadLock lock;
 
         // Check if image has been rotated since last time
-        rotated = preview != nullptr && newLandscape != landscape;
+        rotated = preview && newLandscape != landscape;
 
-        guint8* temp = preview;
-        preview = nullptr;
-        delete [] temp;
-        temp = new guint8 [prew * preh * 3];
-        memcpy (temp, img->getData(), prew * preh * 3);
-        preview = temp;
+        if (resize) {
+            delete [] preview;
+            preview = new guint8 [prew * preh * 3];
+        }
+        memcpy(preview, img->getData(), prew * preh * 3);
         updateBackBuffer ();
     }
 
     landscape = newLandscape;
 
-    img->free ();
+    img->free();
 
-    if (parent != nullptr) {
+    if (parent) {
         if (rotated) {
             parent->thumbRearrangementNeeded();
         } else if (redrawRequests == 0) {
-            parent->redrawNeeded (this);
+            parent->redrawNeeded(this);
         }
     }
 }
diff --git a/rtgui/filecatalog.cc b/rtgui/filecatalog.cc
index 7c14873a2..63ebc7676 100644
--- a/rtgui/filecatalog.cc
+++ b/rtgui/filecatalog.cc
@@ -804,28 +804,28 @@ void FileCatalog::previewsFinishedUI ()
 
     {
         GThreadLock lock; // All GUI access from idle_add callbacks or separate thread HAVE to be protected
-        redrawAll ();
+        redrawAll();
         previewsToLoad = 0;
 
         if (filterPanel) {
-            filterPanel->set_sensitive (true);
+            filterPanel->set_sensitive(true);
 
-            if ( !hasValidCurrentEFS ) {
-                MyMutex::MyLock lock(dirEFSMutex);
+            if (!hasValidCurrentEFS) {
+                MyMutex::MyLock myLock(dirEFSMutex);
                 currentEFS = dirEFS;
-                filterPanel->setFilter ( dirEFS, true );
+                filterPanel->setFilter(dirEFS, true);
             } else {
-                filterPanel->setFilter ( currentEFS, false );
+                filterPanel->setFilter(currentEFS, false);
             }
         }
 
         if (exportPanel) {
-            exportPanel->set_sensitive (true);
+            exportPanel->set_sensitive(true);
         }
 
         // restart anything that might have been loaded low quality
         fileBrowser->refreshQuickThumbImages();
-        fileBrowser->applyFilter (getFilter());  // refresh total image count
+        fileBrowser->applyFilter(getFilter());  // refresh total image count
         _refreshProgressBar();
     }
     filepanel->loadingThumbs(M("PROGRESSBAR_READY"), 0);