added checks to mitigate floating point crashes

src/widgets/Scrollbar.cpp

@@ -276,7 +276,8 @@ void Scrollbar::paintEvent(QPaintEvent *)
 
     int w = this->width();
     float y = 0;
-    float dY = float(this->height()) / float(snapshotLength);
+    float dY =
+        float(this->height()) / std::max<float>(1.0f, float(snapshotLength));
     int highlightHeight =
         int(std::ceil(std::max<float>(this->scale() * 2, dY)));
 
@@ -356,8 +357,10 @@ void Scrollbar::mouseMoveEvent(QMouseEvent *event)
     {
         int delta = event->pos().y() - this->lastMousePosition_.y();
 
-        setDesiredValue(this->desiredValue_ +
-                        qreal(delta) / this->trackHeight_ * this->maximum_);
+        setDesiredValue(
+            this->desiredValue_ +
+            qreal(delta) /
+                std::max<qreal>(0.02, this->trackHeight_ * this->maximum_));
     }
 
     this->lastMousePosition_ = event->pos();
@@ -442,13 +445,11 @@ void Scrollbar::updateScroll()
     this->trackHeight_ = this->height() - this->buttonHeight_ -
                          this->buttonHeight_ - MIN_THUMB_HEIGHT - 1;
 
+    auto div = std::max<qreal>(0.01, this->maximum_ * this->trackHeight_);
+
     this->thumbRect_ =
-        QRect(0,
-              int(this->currentValue_ / this->maximum_ * this->trackHeight_) +
-                  1 + this->buttonHeight_,
-              this->width(),
-              int(this->largeChange_ / this->maximum_ * this->trackHeight_) +
-                  MIN_THUMB_HEIGHT);
+        QRect(0, int(this->currentValue_ / div) + 1 + this->buttonHeight_,
+              this->width(), int(this->largeChange_ / div) + MIN_THUMB_HEIGHT);
 
     this->update();
 }