Re: China assures full support to Pakistan
Perhaps you need it told in simpler terms: Russia was supporting India, but could not do so openly. US initially started supporting Pakistan, China too kept supporting Pakistan, but it could not be seen outright defeating India via Pakistan. That's the world politics.
China did what it could as an ally at the time, under the circumstances. Russia did what it could (Veto power in UN) to help India.
Why does it bother India that Pakistan and China support each other? Everytime Pakistan and China is mentioned Indians take it upon themselves to dissect everything. Inferiority complex? Or just an old habit? (No answer required, just think about it :D)