From 4ae3f7c81ba11796ac6bea0c457ac2ac78897b0d Mon Sep 17 00:00:00 2001
From: sammycage <sammycageagle@gmail.com>
Date: Mon, 23 Sep 2024 12:16:29 +0100
Subject: [PATCH] Add null and zero division checks to avoid undefined
 behavior.

---
 source/graphics.cpp           | 6 ------
 source/svgelement.cpp         | 6 +++---
 source/svggeometryelement.cpp | 2 +-
 source/svgtextelement.cpp     | 2 +-
 4 files changed, 5 insertions(+), 11 deletions(-)

diff --git a/source/graphics.cpp b/source/graphics.cpp
index aab5592..a13b56d 100644
--- a/source/graphics.cpp
+++ b/source/graphics.cpp
@@ -606,8 +606,6 @@ void Canvas::strokePath(const Path& path, const StrokeData& strokeData, const Tr
 
 void Canvas::fillText(const std::u32string_view& text, const Font& font, const Point& origin, const Transform& transform)
 {
-    if(text.empty() || font.isNull())
-        return;
     plutovg_canvas_reset_matrix(m_canvas);
     plutovg_canvas_translate(m_canvas, -m_x, -m_y);
     plutovg_canvas_transform(m_canvas, &transform.matrix());
@@ -653,10 +651,6 @@ void Canvas::clipRect(const Rect& rect, FillRule clipRule, const Transform& tran
 
 void Canvas::drawImage(const Bitmap& image, const Rect& dstRect, const Rect& srcRect, const Transform& transform)
 {
-    if(dstRect.isEmpty() || srcRect.isEmpty()) {
-        return;
-    }
-
     auto xScale = dstRect.w / srcRect.w;
     auto yScale = dstRect.h / srcRect.h;
     plutovg_matrix_t matrix = {xScale, 0, 0, yScale, -srcRect.x * xScale, -srcRect.y * yScale};
diff --git a/source/svgelement.cpp b/source/svgelement.cpp
index c8b337e..61eee7d 100644
--- a/source/svgelement.cpp
+++ b/source/svgelement.cpp
@@ -812,12 +812,12 @@ Rect SVGImageElement::strokeBoundingBox() const
 
 void SVGImageElement::render(SVGRenderState& state) const
 {
-    if(isDisplayNone() || isVisibilityHidden())
-        return;
-    if(!m_image.width() || !m_image.height())
+    if(m_image.isNull() || isDisplayNone() || isVisibilityHidden())
         return;
     Rect dstRect(fillBoundingBox());
     Rect srcRect(0, 0, m_image.width(), m_image.height());
+    if(dstRect.isEmpty() || srcRect.isEmpty())
+        return;
     m_preserveAspectRatio.transformRect(dstRect, srcRect);
 
     SVGBlendInfo blendInfo(this);
diff --git a/source/svggeometryelement.cpp b/source/svggeometryelement.cpp
index 345750e..14819d5 100644
--- a/source/svggeometryelement.cpp
+++ b/source/svggeometryelement.cpp
@@ -138,7 +138,7 @@ void SVGGeometryElement::updateMarkerPositions(SVGMarkerPositionList& positions,
 
 void SVGGeometryElement::render(SVGRenderState& state) const
 {
-    if(isVisibilityHidden() || isDisplayNone())
+    if(m_path.isNull() || isVisibilityHidden() || isDisplayNone())
         return;
     SVGBlendInfo blendInfo(this);
     SVGRenderState newState(this, state, localTransform());
diff --git a/source/svgtextelement.cpp b/source/svgtextelement.cpp
index 211d293..ed1292d 100644
--- a/source/svgtextelement.cpp
+++ b/source/svgtextelement.cpp
@@ -309,7 +309,7 @@ void SVGTextElement::layout(SVGLayoutState& state)
 
 void SVGTextElement::render(SVGRenderState& state) const
 {
-    if(isVisibilityHidden() || isDisplayNone())
+    if(m_text.empty() || isVisibilityHidden() || isDisplayNone())
         return;
     SVGBlendInfo blendInfo(this);
     SVGRenderState newState(this, state, localTransform());