How long will the new China-Russia friendship last?

The split in the late 50’s, the border wars in 1968 that almost went nuclear, Soviet aid to Vietnam in the 1978 Chinese invasion, the Chinese support to the afghan rebels to combat soviet troops in Afghanistan, Beijing’s support to rival Marxist rebels in Angola to undermine Soviet support for their band of troops as well as spending resources on North Korea to keep them from being pro soviet against China can’t be forgotten by Beijing. I can’t help but think China is going to backstab Russia if things go badly for Putin. China is playing it smart by giving moral support to Russia as well as buying up wheat at a favorable price. At least for now….