fixed pending share race error on warm app start

lib/view/pages/files/files_upload_dialog.dart

@@ -187,11 +187,23 @@ class _FilesUploadDialogState extends State<FilesUploadDialog> {
             '${_uploadableFiles.indexOf(file) + 1}/${_uploadableFiles.length}';
       });
 
+      // A vanished source file would otherwise surface as a cryptic
+      // "Content-Length must contain only digits" HttpException, because
+      // statSync reports size -1 for missing files.
+      final fileStat = FileStat.statSync(filePath);
+      if (fileStat.type == FileSystemEntityType.notFound || fileStat.size < 0) {
+        _showUploadError(
+          'Die Datei "$fileName" ist nicht mehr verfügbar. '
+          'Bitte wähle sie erneut aus.',
+        );
+        return;
+      }
+
       final HttpClientResponse uploadTask;
       try {
         uploadTask = await webdavClient.putFile(
           File(filePath),
-          FileStat.statSync(filePath),
+          fileStat,
           PathUri.parse(fullRemotePath),
           onProgress: (progress) {
             setState(() {

lib/view/pages/share_intent/share_chat_picker.dart

@@ -197,7 +197,7 @@ void _setExternalDraftAndOpenChat(
     final settings = context.read<SettingsCubit>();
     settings.val(write: true).talkSettings.drafts[room.token] = share.text!;
   }
-  ShareIntentListener.instance.clear();
+  ShareIntentListener.instance.clear(ifCurrent: share);
   _finishWithChat(context, room);
 }
 

lib/view/pages/share_intent/share_folder_picker.dart

@@ -212,13 +212,18 @@ Future<void> _externalUploadFlow(
     screen: FilesUploadDialog(
       filePaths: share.filePaths,
       remotePath: targetPath.join('/'),
-      onUploadFinished: (_) => _afterExternalUploaded(context, targetPath),
+      onUploadFinished: (_) =>
+          _afterExternalUploaded(context, targetPath, share),
     ),
   );
 }
 
-void _afterExternalUploaded(BuildContext context, List<String> targetPath) {
-  ShareIntentListener.instance.clear();
+void _afterExternalUploaded(
+  BuildContext context,
+  List<String> targetPath,
+  PendingShare share,
+) {
+  ShareIntentListener.instance.clear(ifCurrent: share);
   if (!context.mounted) return;
   _finishWithFolder(context, targetPath);
 }

lib/view/pages/share_intent/share_target_page.dart

@@ -40,7 +40,7 @@ class ShareTargetPage extends StatelessWidget {
   @override
   Widget build(BuildContext context) => PopScope(
     onPopInvokedWithResult: (didPop, _) {
-      if (didPop) ShareIntentListener.instance.clear();
+      if (didPop) ShareIntentListener.instance.clear(ifCurrent: share);
     },
     child: Scaffold(
       appBar: AppBar(title: Text(_appBarTitle())),