r1 history:
3:d350e7209906 Add different subrepository in the same path <- subrepository r2 = ../r3 (9e4a2fef1a1c)
2:4d7b3db8779f Remove subrepository                         <- subrepository removed
1:34017377d9c3 Add subrepository                            <- subrepository r2 = ../r2 (916933c1dd8e)
0:e4eced2b7381 Initial commit

r2 history:
0:916933c1dd8e Initial commit

r3 history:
0:9e4a2fef1a1c Initial commit


http subrepos:

http_r1:
2:3d6694af00e4 third 
1:a2d737193093 second 
0:2516e4a826e8 initial commit

http_r2:
2:7de2f844e1a2 Register subrepo r1 -> r1:1
1:f54386da1b42 add .hgsub
0:97bef7492664 initial

http_r3:
3:999fb1eb9735 Update subrepos -> r1:2, r2:2
2:e1dc5eeb1bec register subrepos -> r1:1, r2:1
1:94b99ee983ed add .hgsub
0:44c53c0ea688 initial