fix: protect GUI report exports from write errors and collisions

MethodenAnalyser3.py

@@ -1382,7 +1382,7 @@ def create_safe_filename(original_path: str, suffix: str) -> str:
 
     # Wenn Datei existiert, nummeriere
     counter = 1
-    while os.path.exists(export_path):
+    while os.path.lexists(export_path):
         export_path = f"{base_path}_{counter}{suffix}"
         counter += 1
 
@@ -1442,12 +1442,18 @@ def run_analysis(output_widget: scrolledtext.ScrolledText, status_widget: tk.Lab
 
     # Export mit Bestätigung
     try:
-        export_path = create_safe_filename(path, "_analysis.txt")
-
-        with open(export_path, "w", encoding="utf-8") as f:
-            f.write(f"{_t('gui_analyzed_file')}: {path}\n")
-            f.write(f"{_t('gui_date')}: {datetime.datetime.now().astimezone().strftime('%Y-%m-%d %H:%M:%S')}\n\n")
-            f.write(generate_report(result))
+        text = (
+            f"{_t('gui_analyzed_file')}: {path}\n"
+            f"{_t('gui_date')}: {datetime.datetime.now().astimezone().strftime('%Y-%m-%d %H:%M:%S')}\n\n"
+            + generate_report(result)
+        )
+        while True:
+            export_path = create_safe_filename(path, "_analysis.txt")
+            try:
+                _write_report_bytes(text.encode("utf-8"), export_path, exclusive=True, label="Text")
+            except FileExistsError:
+                continue
+            break
 
         output_widget.insert(tk.END, f"\n{_t('gui_report_saved')}: {export_path}")
         if status_widget is not None:
@@ -2080,27 +2086,38 @@ def _safe_relpath(p: str) -> str:
 def write_json_report(report: dict[str, Any], output_path: str) -> str:
     """Veröffentlicht einen vollständigen JSON-Report per atomarem Dateitausch."""
     data = (json.dumps(report, indent=2, ensure_ascii=False) + "\n").encode("utf-8")
+    return _write_report_bytes(data, output_path)
+
+
+def _write_report_bytes(
+    data: bytes, output_path: str, *, exclusive: bool = False, label: str = "JSON",
+) -> str:
+    """Write a complete report; publish exclusively or replace atomically."""
     target = os.path.abspath(output_path)
-    destination = pathlib.Path(target).resolve()
+    raw_path = pathlib.Path(target)
+    destination = raw_path.parent.resolve() / raw_path.name if exclusive else raw_path.resolve()
     destination.parent.mkdir(parents=True, exist_ok=True)
-    mode = stat.S_IMODE(destination.stat().st_mode) if destination.exists() else None
+    mode = stat.S_IMODE(destination.stat().st_mode) if not exclusive and destination.exists() else None
     if mode is not None and not mode & (stat.S_IWUSR | stat.S_IWGRP | stat.S_IWOTH):
-        raise PermissionError("JSON report target is read-only")
+        raise PermissionError(f"{label} report target is read-only")
     staged = None
     try:
         with tempfile.NamedTemporaryFile(
             mode="wb", dir=destination.parent,
-            prefix=f".{destination.name}.json-", delete=False,
+            prefix=f".{destination.name}.report-", delete=False,
         ) as handle:
             staged = pathlib.Path(handle.name)
             if handle.write(data) != len(data):
-                raise OSError("Incomplete JSON report write")
+                raise OSError(f"Incomplete {label} report write")
             handle.flush()
             os.fsync(handle.fileno())
         if mode is not None:
             staged.chmod(mode)
-        os.replace(staged, destination)
-        staged = None
+        if exclusive:
+            os.link(staged, destination)
+        else:
+            os.replace(staged, destination)
+            staged = None
     finally:
         if staged is not None:
             staged.chmod(stat.S_IRUSR | stat.S_IWUSR)
@@ -2199,8 +2216,8 @@ def progress_cb(cur, tot, fp):
         output_widget.insert(tk.END, generate_project_report(result))
 
         export_path = os.path.join(folder_path, "project_analysis.txt")
-        with open(export_path, "w", encoding="utf-8") as f:
-            f.write(generate_project_report(result, project_name=_extract_project_display_name(folder_path)))
+        text = generate_project_report(result, project_name=_extract_project_display_name(folder_path))
+        _write_report_bytes(text.encode("utf-8"), export_path, label="Text")
         output_widget.insert(tk.END, f"\n{_t('gui_saved')}: {export_path}")
         if status_widget is not None:
             status_widget.config(text=f"{_t('status_analysis_done')} {os.path.basename(folder_path)}")

README.md

@@ -5,7 +5,7 @@
 <p align="center">
   <a href="https://github.com/dev-bricks/MethodenAnalyser/releases/tag/v3.0.2"><img src="https://img.shields.io/badge/Version-3.0.2-blue?style=for-the-badge" alt="Version 3.0.2"></a>
   <a href="https://github.com/dev-bricks/MethodenAnalyser/actions/workflows/tests.yml"><img src="https://img.shields.io/badge/CI-Passing-success?style=for-the-badge&logo=githubactions&logoColor=white" alt="CI Status"></a>
-  <a href="#development--testing"><img src="https://img.shields.io/badge/Tests-225%20Passed-success?style=for-the-badge&logo=pytest&logoColor=white" alt="Tests 100% Green"></a>
+  <a href="#development--testing"><img src="https://img.shields.io/badge/Tests-231%20Passed-success?style=for-the-badge&logo=pytest&logoColor=white" alt="Tests 100% Green"></a>
   <img src="https://img.shields.io/badge/Python-3.10%20%7C%203.11%20%7C%203.12%20%7C%203.13-yellow?style=for-the-badge&logo=python&logoColor=white" alt="Python 3.10-3.13">
   <img src="https://img.shields.io/badge/Platform-Windows%20%7C%20Linux%20%7C%20macOS-lightgrey?style=for-the-badge" alt="Cross-Platform">
   <img src="https://img.shields.io/badge/GUI-Tkinter%20%2B%20CLI%20%2B%20PWA-orange?style=for-the-badge" alt="GUI Desktop + CLI + PWA">
@@ -349,6 +349,12 @@ See the full [SECURITY.md](SECURITY.md) for detailed policies in English and Ger
 
 ## Development & Testing
 
+GUI text reports use the same flushed, atomic publication as JSON reports.
+The project report replaces its previous version only when complete. Individual
+file reports are published exclusively under a free numbered name, preserving
+files created concurrently. Exclusive publication requires hard-link support;
+an unsupported filesystem produces an export error instead of overwriting.
+
 ```bash
 # Verify Python syntax and AST compilation
 python -m py_compile MethodenAnalyser3.py manage_translations.py translator.py webapp/server.py

README_de.md

@@ -5,7 +5,7 @@
 <p align="center">
   <a href="https://github.com/dev-bricks/MethodenAnalyser/releases/tag/v3.0.2"><img src="https://img.shields.io/badge/Version-3.0.2-blue?style=for-the-badge" alt="Version 3.0.2"></a>
   <a href="https://github.com/dev-bricks/MethodenAnalyser/actions/workflows/tests.yml"><img src="https://img.shields.io/badge/CI-Bestanden-success?style=for-the-badge&logo=githubactions&logoColor=white" alt="CI-Status"></a>
-  <a href="#entwicklung--tests"><img src="https://img.shields.io/badge/Tests-225%20Bestanden-success?style=for-the-badge&logo=pytest&logoColor=white" alt="Tests 100% Grün"></a>
+  <a href="#entwicklung--tests"><img src="https://img.shields.io/badge/Tests-231%20Bestanden-success?style=for-the-badge&logo=pytest&logoColor=white" alt="Tests 100% Grün"></a>
   <img src="https://img.shields.io/badge/Python-3.10%20%7C%203.11%20%7C%203.12%20%7C%203.13-yellow?style=for-the-badge&logo=python&logoColor=white" alt="Python 3.10-3.13">
   <img src="https://img.shields.io/badge/Plattform-Windows%20%7C%20Linux%20%7C%20macOS-lightgrey?style=for-the-badge" alt="Plattformübergreifend">
   <img src="https://img.shields.io/badge/GUI-Tkinter%20%2B%20CLI%20%2B%20PWA-orange?style=for-the-badge" alt="GUI Desktop + CLI + PWA">
@@ -352,6 +352,13 @@ Vollständige Richtlinie siehe [SECURITY.md](SECURITY.md).
 
 ## Entwicklung & Tests
 
+Textberichte der GUI verwenden dieselbe vollständig geschriebene, atomare
+Veröffentlichung wie JSON-Berichte. Der Projektbericht ersetzt seinen Vorläufer
+erst nach vollständigem Schreiben. Einzelberichte werden exklusiv unter einem
+freien, gegebenenfalls nummerierten Namen angelegt; zwischenzeitlich entstandene
+Dateien bleiben erhalten. Dafür muss das Dateisystem Hard Links unterstützen;
+andernfalls meldet die GUI einen Exportfehler.
+
 ```bash
 # Syntax- und Bytecode-Prüfung
 python -m py_compile MethodenAnalyser3.py manage_translations.py translator.py webapp/server.py

llms.txt

@@ -23,6 +23,7 @@ MethodenAnalyser analyzes Python files and project folders locally with Python A
 - CLI file analysis: `python MethodenAnalyser3.py --file path/to/file.py`.
 - CLI project analysis: `python MethodenAnalyser3.py --project path/to/project`.
 - JSON export: add `--json-output` or pass a target JSON filename.
+- GUI text reports share atomic report staging. Project reports replace complete previous outputs; file reports publish exclusively via a same-directory hard link and retry numbered names on collisions. Existing files, including dangling symlinks, are not overwritten. Hard-link support is required for exclusive publication; unsupported filesystems fail with a GUI export error.
 - JSON report publication serializes first, writes and fsyncs a same-directory temporary file, then replaces the destination atomically. Failures before replacement preserve previous bytes; read-only destinations are rejected. Existing report symlinks remain links; replacement changes the destination inode and does not update other hard-link names. This is not a concurrent-writer lock or a directory-fsync crash-durability guarantee.
 - CLI JSON export rejects targets that alias analyzed sources (including hard links, symbolic links, and project files with analysis errors); exit code 1, no source write. This check does not lock against concurrent path changes.
 - Local web helper: `python webapp/server.py` or `START_WEBAPP.bat`; its API accepts `snippet`, `file` and `zip`, while `project` is import-only.

tests/test_gui_report_publication.py

@@ -0,0 +1,92 @@
+from unittest.mock import Mock
+
+import pytest
+
+import MethodenAnalyser3 as app
+
+
+def prepare_file(monkeypatch, tmp_path):
+    source = tmp_path / "source.py"
+    source.write_text("print('Grüße')\n", encoding="utf-8")
+    monkeypatch.setattr(app.filedialog, "askopenfilename", lambda **_kw: str(source))
+    monkeypatch.setattr(app, "messagebox", Mock())
+    return source
+
+
+def test_formatting_failure_does_not_create_partial_file_report(tmp_path, monkeypatch):
+    prepare_file(monkeypatch, tmp_path)
+    monkeypatch.setattr(app, "generate_report", Mock(side_effect=["display", RuntimeError("format failure")]))
+    app.run_analysis(Mock(), Mock())
+    assert not (tmp_path / "source_analysis.txt").exists()
+    app.messagebox.showwarning.assert_called_once()
+
+
+def test_project_replace_error_preserves_previous_report(tmp_path, monkeypatch):
+    report = tmp_path / "project_analysis.txt"
+    report.write_bytes(b"previous report")
+    monkeypatch.setattr(app.filedialog, "askdirectory", lambda **_kw: str(tmp_path))
+    monkeypatch.setattr(app, "messagebox", Mock())
+
+    def fail(*_args):
+        raise OSError("replace failure")
+
+    monkeypatch.setattr(app.os, "replace", fail)
+    app.run_project_analysis(Mock(), Mock())
+    assert report.read_bytes() == b"previous report"
+    assert sorted(p.name for p in tmp_path.iterdir()) == ["project_analysis.txt"]
+    app.messagebox.showerror.assert_called_once()
+
+
+def test_concurrent_file_report_is_preserved_and_export_gets_new_name(tmp_path, monkeypatch):
+    prepare_file(monkeypatch, tmp_path)
+    monkeypatch.setattr(app, "generate_report", lambda _result: "EXPORT Grüße")
+    first = tmp_path / "source_analysis.txt"
+    actual_link = app.os.link
+    actual_choose = app.create_safe_filename
+    attempts = []
+
+    def choose(*args):
+        chosen = actual_choose(*args)
+        if not first.exists():
+            first.write_bytes(b"concurrent report")
+        return chosen
+
+    def publish(staged, destination):
+        attempts.append(destination)
+        return actual_link(staged, destination)
+
+    monkeypatch.setattr(app, "create_safe_filename", choose)
+    monkeypatch.setattr(app.os, "link", publish)
+    app.run_analysis(Mock(), Mock())
+    assert first.read_bytes() == b"concurrent report"
+    assert "EXPORT Grüße" in (tmp_path / "source_1_analysis.txt").read_text(encoding="utf-8")
+    assert len(attempts) == 2
+    assert sorted(p.name for p in tmp_path.iterdir()) == ["source.py", "source_1_analysis.txt", "source_analysis.txt"]
+    app.messagebox.showwarning.assert_not_called()
+
+
+@pytest.mark.parametrize("failure", ["fsync", "link"])
+def test_file_report_publication_failure_leaves_no_partial_output(tmp_path, monkeypatch, failure):
+    source = prepare_file(monkeypatch, tmp_path)
+    original = source.read_bytes()
+
+    def fail(*_args):
+        raise OSError("publication failure")
+
+    monkeypatch.setattr(app.os, failure, fail)
+    app.run_analysis(Mock(), Mock())
+    assert source.read_bytes() == original
+    assert sorted(p.name for p in tmp_path.iterdir()) == ["source.py"]
+    app.messagebox.showwarning.assert_called_once()
+
+
+def test_project_report_success_replaces_previous_content(tmp_path, monkeypatch):
+    report = tmp_path / "project_analysis.txt"
+    report.write_bytes(b"previous report")
+    monkeypatch.setattr(app.filedialog, "askdirectory", lambda **_kw: str(tmp_path))
+    monkeypatch.setattr(app, "messagebox", Mock())
+    monkeypatch.setattr(app, "generate_project_report", lambda *_args, **_kwargs: "REPORT Grüße")
+    app.run_project_analysis(Mock(), Mock())
+    assert report.read_text(encoding="utf-8") == "REPORT Grüße"
+    assert sorted(p.name for p in tmp_path.iterdir()) == ["project_analysis.txt"]
+    app.messagebox.showerror.assert_not_called()