File ImageVariableGroup.patch of Package hugin

--- hugin-2018.0.0/src/hugin_base/panodata/ImageVariableGroup.cpp	2016-01-24 09:50:34.000000000 +0100
+++ hugin-2018.0.0/src/hugin_base/panodata/ImageVariableGroup.cpp	2018-06-21 21:08:15.000000000 +0200
@@ -289,6 +289,7 @@
     m_image_part_numbers.push_back(0);
     for (std::size_t i = 1; i < m_pano.getNrOfImages(); i++)
     {
+        const SrcPanoImage &i_image = m_pano.getImage(i);
         // find a part for this image.
         /* We use parts_first_image.size() as a flag to determine when the
          * images is not linked to any part we have previously found, as it
@@ -296,6 +297,7 @@
         std::size_t part_number = parts_first_image.size();;
         for (std::size_t j = 0; j < parts_first_image.size(); j++)
         {
+            const SrcPanoImage &j_image = m_pano.getImage(parts_first_image[j]);
             // check each variable in the group
             for (std::set<ImageVariableEnum>::const_iterator k = m_variables.begin();
                  (k != m_variables.end()) && (part_number != j); ++k)
@@ -307,7 +309,7 @@
                      */
 #define image_variable( name, type, default_value ) \
                     case IVE_##name:\
-                        if (m_pano.getImage(i).name##isLinkedWith(m_pano.getImage(parts_first_image[j]))) \
+                        if (i_image.name##isLinkedWith(j_image)) \
                             part_number = j;\
                         break;
 #include "image_variables.h"