Check that the m_closedShape has a size > 0 before using the iterator

An iterator on m_closedShape is being created and used without checking
if the iterator actually has a valid value. This was not a problem in
Qt5, but in Qt6 causes a crash. This patch adds a check to the QMap, so
that the iterator is not even created if the QMap has a size of 0

Change-Id: Ie7a3ce2ad162bb787fbbb18674bbf9bd95524453
Reviewed-by: Rebecca Worledge <rebecca.worledge@qt.io>

1 files changed, 45 insertions, 43 deletions

diff --git a/src/bodymovin/bmfreeformshape.cpp b/src/bodymovin/bmfreeformshape.cpp
index fd5c46b..07133e0 100644
--- a/src/bodymovin/bmfreeformshape.cpp
+++ b/src/bodymovin/bmfreeformshape.cpp
@@ -170,62 +170,64 @@ void BMFreeFormShape::buildShape(const QJsonObject &shape)
 
 void BMFreeFormShape::buildShape(int frame)
 {
-    auto it = m_closedShape.constBegin();
-    bool found = false;
-
-    if (frame <= it.key())
-        found = true;
-    else {
-        while (it != m_closedShape.constEnd()) {
-            if (it.key() <= frame) {
-                found = true;
-                break;
+    if (m_closedShape.size()) {
+        auto it = m_closedShape.constBegin();
+        bool found = false;
+
+        if (frame <= it.key())
+            found = true;
+        else {
+            while (it != m_closedShape.constEnd()) {
+                if (it.key() <= frame) {
+                    found = true;
+                    break;
+                }
+                ++it;
             }
-            ++it;
         }
-    }
 
-    bool needToClose = false;
-    if (found)
-        needToClose = (*it);
+        bool needToClose = false;
+        if (found)
+            needToClose = (*it);
 
-    // If there are less than two vertices, cannot make a bezier curve
-    if (m_vertexList.count() < 2)
-        return;
+        // If there are less than two vertices, cannot make a bezier curve
+        if (m_vertexList.count() < 2)
+            return;
 
-    QPointF s(m_vertexList.at(0).pos.value());
-    QPointF s0(s);
+        QPointF s(m_vertexList.at(0).pos.value());
+        QPointF s0(s);
 
-    m_path.moveTo(s);
-    int i=0;
+        m_path.moveTo(s);
+        int i = 0;
 
-    while (i < m_vertexList.count() - 1) {
-        QPointF v = m_vertexList.at(i + 1).pos.value();
-        QPointF c1 = m_vertexList.at(i).co.value();
-        QPointF c2 = m_vertexList.at(i + 1).ci.value();
-        c1 += s;
-        c2 += v;
+        while (i < m_vertexList.count() - 1) {
+            QPointF v = m_vertexList.at(i + 1).pos.value();
+            QPointF c1 = m_vertexList.at(i).co.value();
+            QPointF c2 = m_vertexList.at(i + 1).ci.value();
+            c1 += s;
+            c2 += v;
 
-        m_path.cubicTo(c1, c2, v);
+            m_path.cubicTo(c1, c2, v);
 
-        s = v;
-        i++;
-    }
+            s = v;
+            i++;
+        }
 
-    if (needToClose) {
-        QPointF v = s0;
-        QPointF c1 = m_vertexList.at(i).co.value();
-        QPointF c2 = m_vertexList.at(0).ci.value();
-        c1 += s;
-        c2 += v;
+        if (needToClose) {
+            QPointF v = s0;
+            QPointF c1 = m_vertexList.at(i).co.value();
+            QPointF c2 = m_vertexList.at(0).ci.value();
+            c1 += s;
+            c2 += v;
 
-        m_path.cubicTo(c1, c2, v);
-    }
+            m_path.cubicTo(c1, c2, v);
+        }
 
-    m_path.setFillRule(Qt::WindingFill);
+        m_path.setFillRule(Qt::WindingFill);
 
-    if (m_direction)
-        m_path = m_path.toReversed();
+        if (m_direction)
+            m_path = m_path.toReversed();
+    }
 }
 
 void BMFreeFormShape::parseEasedVertices(const QJsonObject &keyframe, int startFrame)