Fix an isnan() issue on (at least) MinGW and Mac OS X.

This closes bug #531.

diff --git a/pv/view/viewport.cpp b/pv/view/viewport.cpp
index 6b85e1b79d324c4788afc40b5903b02e0497d826..d9be32c996ee142b44603d1c9097a9bcde93295a 100644 (file)
--- a/pv/view/viewport.cpp
+++ b/pv/view/viewport.cpp
@@ -82,7 +82,8 @@ void Viewport::drag()
 
 void Viewport::drag_by(const QPoint &delta)
 {
-       if (isnan(drag_offset_))
+       // Use std::isnan() instead of isnan(), the latter can cause issues.
+       if (std::isnan(drag_offset_))
                return;
 
        view_.set_scale_offset(view_.scale(), drag_offset_ -