Merge branch 'fix-out-of-bounds-bug' into 'master'

Fix possible out of bounds errors in AddToImage()

See merge request !119

include/schaapcommon/facets/facetimage.h

@@ -119,7 +119,10 @@ class FacetImage {
 
   /**
    * Add this facet to the provided full image and weight image,
-   * using a specified weight mask.
+   * using a specified weight mask. In case the facet extends beyond
+   * the right (high x) or bottom (high y) edges, the facet image is
+   * trimmed on this side to fall inside the full image. This
+   * situation might arise because of the alignment requirements.
    * @param[in,out] image  Full image to which the data from this facet will be
    * added.
    * @param[in,out] weight Weight image (same size as the full image) that will

src/facets/facetimage.cc

@@ -135,8 +135,12 @@ void FacetImage::AddWithMask(float* image, float* weight,
   float* image_y = image + OffsetY() * image_width_ + OffsetX();
   float* weight_y = weight + OffsetY() * image_width_ + OffsetX();
 
-  for (size_t y = 0; y != Height(); ++y) {
-    for (size_t x = 0; x != Width(); ++x) {
+  // Because of alignment, the facet's bounding box may slightly extend past
+  // the full image size, so make sure not to cross the boundary:
+  const size_t max_x = std::min(Width(), image_width_ - OffsetX());
+  const size_t max_y = std::min(Height(), image_height_ - OffsetY());
+  for (size_t y = 0; y != max_y; ++y) {
+    for (size_t x = 0; x != max_x; ++x) {
       // Note that OffsetX() was already added above to image_y
       image_y[x] += mask_y[x] * data_y[x];
       weight_y[x] += mask_y[x];