From a8a477ae6785458eef35c237aa7da5aff15fa80c Mon Sep 17 00:00:00 2001
From: Aleix Pol <aleixpol@kde.org>
Date: Fri, 23 Sep 2022 18:04:43 +0200
Subject: [PATCH] pcx: Do not support sequential devices

We need QIODevice::pos() to work in QDataStream &operator>>.

BUG: 459541
---
 src/imageformats/pcx.cpp | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/imageformats/pcx.cpp b/src/imageformats/pcx.cpp
index ddde33e..e9b0a23 100644
--- a/src/imageformats/pcx.cpp
+++ b/src/imageformats/pcx.cpp
@@ -684,6 +684,12 @@ bool PCXHandler::canRead(QIODevice *device)
         return false;
     }
 
+    // We do not support sequential images
+    // We need to know the current position to properly read the header
+    if (device->isSequential()) {
+        return false;
+    }
+
     qint64 oldPos = device->pos();
 
     char head[1];