disable vignetting or distortion correction checkboxes if the selected lensfun profile doesn't support them

Patch by heckflosse

rtengine/rtlensfun.cc

@@ -215,6 +215,24 @@ float LFLens::getCropFactor() const
     }
 }
 
+bool LFLens::hasVignettingCorrection() const
+{
+    if (data_) {
+        return data_->CalibVignetting;
+    } else {
+        return false;
+    }
+}
+
+bool LFLens::hasDistortionCorrection() const
+{
+    if (data_) {
+        return data_->CalibDistortion;
+    } else {
+        return false;
+    }
+}
+
 
 //-----------------------------------------------------------------------------
 // LFDatabase

rtengine/rtlensfun.h

@@ -76,6 +76,8 @@ public:
     Glib::ustring getLens() const;
     Glib::ustring getDisplayString() const { return getLens(); }
     float getCropFactor() const;
+    bool hasVignettingCorrection() const;
+    bool hasDistortionCorrection() const;
 private:
     friend class LFDatabase;
     const lfLens *data_;

rtgui/lensprofile.cc

@@ -250,6 +250,8 @@ void LensProfilePanel::updateLensfunWarning()
         if (l.getCropFactor() - c.getCropFactor() >= 0.01) {
             warning->show();
         }
+        ckbUseVign->set_sensitive(l.hasVignettingCorrection());
+        ckbUseDist->set_sensitive(l.hasDistortionCorrection());
     }
 }