OCCT

restore [locate_data_file bug29481_ex3.brep] s
explode s f

# remove the gap in both solids
compound s_7 s_8 s_9 s_11 s_12 s_17 gap
removefeatures result s gap
checkshape result
checkprops result -s 1200 -v 2000
checknbshapes result -vertex 12 -edge 20 -wire 11 -face 11 -shell 2 -solid 2
CheckIsFeatureRemoved gap {v e f}

# get history of the operation
savehistory rf_hist

# check that the common face is still shared
if {![regexp "OK" [bopcheck result]]} {
  puts "Error: sharing is lost after removal"
}

# check modification of the common face
modified m6 rf_hist s_6
checkprops m6 -s 100
checknbshapes m6 -vertex 4 -edge 4 -wire 1 -face 1