Merge pull request #2451 from catree:fix_GMSMatcher_crash

modules/xfeatures2d/src/gms.cpp

@@ -370,7 +370,7 @@ int GMSMatcher::run(const int rotationType)
         // Mark inliers
         for (size_t i = 0; i < mNumberMatches; i++)
         {
-            if (mCellPairs[mvMatchPairs[i].first] == mvMatchPairs[i].second)
+            if (mvMatchPairs[i].first >= 0 && mCellPairs[mvMatchPairs[i].first] == mvMatchPairs[i].second)
                 mvbInlierMask[i] = true;
         }
     }