Handle the check of binary versus ascii STL files more robustly

Task-number: QTBUG-67552
Change-Id: I30fc50415f155ce990e72287a99bfca35fcf9713
Reviewed-by: Laszlo Agocs <laszlo.agocs@qt.io>

1 files changed, 17 insertions, 10 deletions

diff --git a/src/plugins/geometryloaders/default/stlgeometryloader.cpp b/src/plugins/geometryloaders/default/stlgeometryloader.cpp
index b4b5333cb..1b1dfb2fe 100644
--- a/src/plugins/geometryloaders/default/stlgeometryloader.cpp
+++ b/src/plugins/geometryloaders/default/stlgeometryloader.cpp
@@ -50,25 +50,29 @@ Q_LOGGING_CATEGORY(StlGeometryLoaderLog, "Qt3D.StlGeometryLoader", QtWarningMsg)
 
 bool StlGeometryLoader::doLoad(QIODevice *ioDev, const QString &subMesh)
 {
-    char signature[5];
-
     Q_UNUSED(subMesh);
 
-    if (ioDev->peek(signature, sizeof(signature)) != sizeof(signature))
-        return false;
-
-    if (!qstrncmp(signature, "solid", 5))
-        return loadAscii(ioDev);
-    else
-        return loadBinary(ioDev);
+    if (loadBinary(ioDev))
+        return true;
 
-    return true;
+    return loadAscii(ioDev);
 }
 
 bool StlGeometryLoader::loadAscii(QIODevice *ioDev)
 {
     // TODO stricter syntax checking
 
+    ioDev->setTextModeEnabled(true);
+    if (!ioDev->seek(0))
+        return false;
+
+    char signature[5];
+    if (ioDev->peek(signature, sizeof(signature)) != sizeof(signature))
+        return false;
+
+    if (qstrncmp(signature, "solid", 5) != 0)
+        return false;
+
     while (!ioDev->atEnd()) {
         QByteArray lineBuffer = ioDev->readLine();
 
@@ -109,6 +113,9 @@ bool StlGeometryLoader::loadBinary(QIODevice *ioDev)
     quint32 triangleCount;
     stream >> triangleCount;
 
+    if (ioDev->size() != headerSize + sizeof(quint32) + (triangleCount * 50))
+        return false;
+
     m_points.reserve(triangleCount * 3);
     m_indices.reserve(triangleCount * 3);