TextEditor: Fix crash on reloading the document

as part of the reload operation we set the document to nullptr inside
TextBlockUserData::documentClosing, but we do not remove the mark from
the marks cache. So when a text mark gets deleted while a document is
reloaded the mark does not get readded to the document, but it wont get
removed from the marks cache inside the document either, so we have to
manually make sure the mark is removed from the cache in this situation.

Fixes: QTCREATORBUG-29432
Change-Id: I3ae4182c4d2bbd3426c1d7a60275d21ac20ea99a
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>
Reviewed-by: Jarek Kobus <jaroslaw.kobus@qt.io>

src/plugins/texteditor/textdocument.cpp

@@ -837,7 +837,7 @@ bool TextDocument::reload(QString *errorString, const FilePath &realFilePath)
     auto documentLayout =
         qobject_cast<TextDocumentLayout*>(d->m_document.documentLayout());
     if (documentLayout)
-        documentLayout->documentAboutToReload(); // removes text marks non-permanently
+        documentLayout->documentAboutToReload(this); // removes text marks non-permanently
 
     bool success = openImpl(errorString, filePath(), realFilePath, /*reload =*/true)
                    == OpenResult::Success;

src/plugins/texteditor/textdocumentlayout.cpp

@@ -4,9 +4,14 @@
 #include "textdocumentlayout.h"
 #include "fontsettings.h"
 #include "textdocument.h"
+#include "texteditorplugin.h"
 #include "texteditorsettings.h"
+
 #include <utils/qtcassert.h>
+#include <utils/temporarydirectory.h>
+
 #include <QDebug>
+#include <QTest>
 
 namespace TextEditor {
 
@@ -667,11 +672,15 @@ TextMarks TextDocumentLayout::documentClosing()
     return marks;
 }
 
-void TextDocumentLayout::documentAboutToReload()
+void TextDocumentLayout::documentAboutToReload(TextDocument *baseTextDocument)
 {
     m_reloadMarks = documentClosing();
-    for (TextMark *mark : std::as_const(m_reloadMarks))
+    for (TextMark *mark : std::as_const(m_reloadMarks)) {
-        mark->setDeleteCallback([this, mark] { m_reloadMarks.removeOne(mark); });
+        mark->setDeleteCallback([this, mark, baseTextDocument] {
+            baseTextDocument->removeMarkFromMarksCache(mark);
+            m_reloadMarks.removeOne(mark);
+        });
+    }
 }
 
 void TextDocumentLayout::documentReloaded(TextDocument *baseTextDocument)
@@ -860,4 +869,23 @@ TextSuggestion::TextSuggestion()
 
 TextSuggestion::~TextSuggestion() = default;
 
+#ifdef WITH_TESTS
+
+void Internal::TextEditorPlugin::testDeletingMarkOnReload()
+{
+    auto doc = new TextDocument();
+    doc->setFilePath(Utils::TemporaryDirectory::masterDirectoryFilePath() / "TestMarkDoc.txt");
+    doc->setPlainText("asd");
+    auto documentLayout = qobject_cast<TextDocumentLayout *>(doc->document()->documentLayout());
+    QVERIFY(documentLayout);
+    auto mark = new TextMark(doc, 1, TextMarkCategory{"testMark","testMark"});
+    QVERIFY(doc->marks().contains(mark));
+    documentLayout->documentAboutToReload(doc); // removes text marks non-permanently
+    delete mark;
+    documentLayout->documentReloaded(doc); // re-adds text marks
+    QVERIFY(!doc->marks().contains(mark));
+}
+
+#endif
+
 } // namespace TextEditor

src/plugins/texteditor/textdocumentlayout.h

@@ -246,7 +246,7 @@ public:
     QRectF blockBoundingRect(const QTextBlock &block) const override;
 
     TextMarks documentClosing();
-    void documentAboutToReload();
+    void documentAboutToReload(TextDocument *baseTextDocument);
     void documentReloaded(TextDocument *baseextDocument);
     void updateMarksLineNumber();
     void updateMarksBlock(const QTextBlock &block);

src/plugins/texteditor/texteditorplugin.h

@@ -40,6 +40,8 @@ private slots:
 
     void testFormatting_data();
     void testFormatting();
+
+    void testDeletingMarkOnReload();
 #endif
 };