Fix "Detach templates" not working when export target is the same file

src/tiled/document.cpp

@@ -313,6 +313,11 @@ void Document::setIgnoreBrokenLinks(bool ignoreBrokenLinks)
     emit ignoreBrokenLinksChanged(ignoreBrokenLinks);
 }
 
+void Document::refreshLastSaved(const QString &fileName)
+{
+    mLastSaved = QFileInfo(fileName).lastModified();
+}
+
 void Document::setChangedOnDisk(bool changedOnDisk)
 {
     mChangedOnDisk = changedOnDisk;

src/tiled/document.h

@@ -93,6 +93,7 @@ class Document : public QObject,
     virtual FileFormat *writerFormat() const = 0;
 
     QDateTime lastSaved() const { return mLastSaved; }
+    void refreshLastSaved(const QString &fileName);
 
     QUndoStack *undoStack() const;
     bool isModified() const;

src/tiled/exporthelper.cpp

@@ -24,6 +24,8 @@
 #include "objectgroup.h"
 #include "wangset.h"
 
+#include <QFileInfo>
+
 namespace Tiled {
 
 /**
@@ -106,8 +108,15 @@ const Map *ExportHelper::prepareExportMap(const Map *map, std::unique_ptr<Map> &
     // Make a copy to which export options are applied
     exportMap = map->clone();
 
-    // We don't want to save the export options in the exported file
-    if (hasExportSettings) {
+    // We don't want to save the export options in the exported file,
+    // unless we're exporting to the same file (to preserve the export settings
+    // so they can be picked up again on the next save)
+    const auto canonicalMapFile = QFileInfo(map->fileName).canonicalFilePath();
+    const auto canonicalExportFile = QFileInfo(map->exportFileName).canonicalFilePath();
+    const bool isSelfExport = !canonicalMapFile.isEmpty()
+            && canonicalMapFile == canonicalExportFile;
+
+    if (hasExportSettings && !isSelfExport) {
         exportMap->exportFileName.clear();
         exportMap->exportFormat.clear();
     }

src/tiled/mainwindow.cpp

@@ -1342,6 +1342,10 @@ bool MainWindow::exportDocument(Document *document)
 
             if (exportFormat->write(map, exportFileName, exportHelper.formatOptions())) {
                 statusBar()->showMessage(tr("Exported to %1").arg(exportFileName), 3000);
+                // When exporting to the same file, update the saved timestamp
+                // to avoid triggering an unnecessary auto-reload
+                if (exportFileName == document->fileName())
+                    document->refreshLastSaved(exportFileName);
                 return true;
             }
 
@@ -1356,6 +1360,10 @@ bool MainWindow::exportDocument(Document *document)
 
             if (exportFormat->write(*tileset, exportFileName, exportHelper.formatOptions())) {
                 statusBar()->showMessage(tr("Exported to %1").arg(exportFileName), 3000);
+                // When exporting to the same file, update the saved timestamp
+                // to avoid triggering an unnecessary auto-reload
+                if (exportFileName == document->fileName())
+                    document->refreshLastSaved(exportFileName);
                 return true;
             }
 
@@ -2432,6 +2440,10 @@ void MainWindow::exportMapAs(MapDocument *mapDocument)
         // Remember export parameters, so subsequent exports can be done faster
         mapDocument->setLastExportFileName(exportDetails.mFileName);
         mapDocument->setExportFormat(exportDetails.mFormat);
+        // When exporting to the same file, update the saved timestamp to avoid
+        // triggering an unnecessary auto-reload
+        if (exportDetails.mFileName == mapDocument->fileName())
+            mapDocument->refreshLastSaved(exportDetails.mFileName);
     }
 }
 
@@ -2471,6 +2483,10 @@ void MainWindow::exportTilesetAs(TilesetDocument *tilesetDocument)
         // Remember export parameters, so subsequent exports can be done faster
         tilesetDocument->setLastExportFileName(exportDetails.mFileName);
         tilesetDocument->setExportFormat(exportDetails.mFormat);
+        // When exporting to the same file, update the saved timestamp to avoid
+        // triggering an unnecessary auto-reload
+        if (exportDetails.mFileName == tilesetDocument->fileName())
+            tilesetDocument->refreshLastSaved(exportDetails.mFileName);
     }
 }