From 1b1ab2387e70194d79e6ce54b993203519e3a680 Mon Sep 17 00:00:00 2001
From: Albert S <mail@quitesimple.org>
Date: Sat, 22 Oct 2022 15:08:26 +0200
Subject: [PATCH] gui: PreviewGeneratorPdf: Guard cache lookup with mutex

No guarantes the read-only lookup is thread-safe so better
just lock there too
---
 gui/previewgeneratorpdf.cpp | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/gui/previewgeneratorpdf.cpp b/gui/previewgeneratorpdf.cpp
index 175a934..8c1b5a9 100644
--- a/gui/previewgeneratorpdf.cpp
+++ b/gui/previewgeneratorpdf.cpp
@@ -7,10 +7,12 @@ static QMutex cacheMutex;
 
 Poppler::Document *PreviewGeneratorPdf::document(QString path)
 {
+	QMutexLocker locker(&cacheMutex);
 	if(documentcache.contains(path))
 	{
 		return documentcache.value(path);
 	}
+	locker.unlock();
 	Poppler::Document *result = Poppler::Document::load(path);
 	if(result == nullptr)
 	{
@@ -19,7 +21,7 @@ Poppler::Document *PreviewGeneratorPdf::document(QString path)
 	}
 	result->setRenderHint(Poppler::Document::TextAntialiasing);
 
-	QMutexLocker locker(&cacheMutex);
+	locker.relock();
 	documentcache.insert(path, result);
 	locker.unlock();
 	return result;