Prompt the user for saving a merged pdf (bug 2034461)

test/integration/reorganize_pages_spec.mjs

@@ -3096,5 +3096,32 @@ describe("Reorganize Pages View", () => {
         })
       );
     });
+
+    it("must mark document as needing save after merge (bug 2034461)", async () => {
+      await Promise.all(
+        pages.map(async ([browserName, page]) => {
+          await waitForThumbnailVisible(page, 1);
+
+          const handleMerged = await createPromise(page, resolve => {
+            window.PDFViewerApplication.eventBus._on(
+              "thumbnailsloaded",
+              resolve,
+              { once: true }
+            );
+          });
+
+          const picker = await page.$("#viewsManagerAddFilePicker");
+          await picker.uploadFile(
+            path.join(__dirname, "../pdfs/three_pages_with_number.pdf")
+          );
+          await awaitPromise(handleMerged);
+
+          const hasChanges = await page.evaluate(() =>
+            window.PDFViewerApplication._hasChanges()
+          );
+          expect(hasChanges).withContext(`In ${browserName}`).toBeTrue();
+        })
+      );
+    });
   });
 });

web/app.js

@@ -1352,6 +1352,8 @@ const PDFViewerApplication = {
         ? this.save()
         : this.download());
     }
+    delete this._mergedDocumentNeedsSaving;
+    this.setTitle();
     classList.remove("wait");
   },
 
@@ -1898,7 +1900,8 @@ const PDFViewerApplication = {
   _hasChanges() {
     return (
       this.pdfDocument?.annotationStorage.size > 0 ||
-      this.pdfThumbnailViewer?.hasStructuralChanges()
+      this.pdfThumbnailViewer?.hasStructuralChanges() ||
+      this._mergedDocumentNeedsSaving === true
     );
   },
 
@@ -2436,6 +2439,7 @@ const PDFViewerApplication = {
       );
       return;
     }
+    this._mergedDocumentNeedsSaving = true;
     this.open({
       data: modifiedPdfBytes,
       filename: this._docFilename,