From 45548ffe73f194501667a8cf982525c146e87285 Mon Sep 17 00:00:00 2001
From: Volker Hilsheimer <volker.hilsheimer@qt.io>
Date: Thu, 9 Jul 2020 10:36:26 +0200
Subject: Don't divide by zero

Fixes: oss-fuzz-23731
Change-Id: Ib21a32a30f7a204d263e6710f17567d91c6aae79
Reviewed-by: Robert Loehning <robert.loehning@qt.io>
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
(cherry picked from commit a7941a5b82e1b8397e9d5f20e5a68c8aac37fb51)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
---
 src/svg/qsvghandler.cpp                      | 3 +++
 tests/auto/qsvgrenderer/tst_qsvgrenderer.cpp | 8 ++++++++
 2 files changed, 11 insertions(+)

diff --git a/src/svg/qsvghandler.cpp b/src/svg/qsvghandler.cpp
index 98a87e1..842af02 100644
--- a/src/svg/qsvghandler.cpp
+++ b/src/svg/qsvghandler.cpp
@@ -1533,6 +1533,9 @@ static void pathArc(QPainterPath &path,
                     qreal               y,
                     qreal curx, qreal cury)
 {
+    if (!rx || !ry)
+        return;
+
     qreal sin_th, cos_th;
     qreal a00, a01, a10, a11;
     qreal x0, y0, x1, y1, xc, yc;
diff --git a/tests/auto/qsvgrenderer/tst_qsvgrenderer.cpp b/tests/auto/qsvgrenderer/tst_qsvgrenderer.cpp
index 686c854..f76a1b2 100644
--- a/tests/auto/qsvgrenderer/tst_qsvgrenderer.cpp
+++ b/tests/auto/qsvgrenderer/tst_qsvgrenderer.cpp
@@ -82,6 +82,7 @@ private slots:
     void smallFont();
     void styleSheet();
     void duplicateStyleId();
+    void oss_fuzz_23731();
 
 #ifndef QT_NO_COMPRESS
     void testGzLoading();
@@ -1605,5 +1606,12 @@ void tst_QSvgRenderer::duplicateStyleId()
     renderer.render(&painter);
 }
 
+void tst_QSvgRenderer::oss_fuzz_23731()
+{
+    // when configured with "-sanitize undefined", this resulted in:
+    // "runtime error: division by zero"
+    QSvgRenderer().load(QByteArray("<svg><path d=\"A4------\">"));
+}
+
 QTEST_MAIN(tst_QSvgRenderer)
 #include "tst_qsvgrenderer.moc"
-- 
cgit v1.2.1