H1B STAMPING: passport expires before last date of I-797 validity

[A4PP]

Hello All:

I recently transitioned from F1 visa to H1B visa. My I-797 validity ends in Sept 2021. It also has an attached I-94 at the bottom with the same validity end date.

I am planning to visit india in May 2019 for stamping. I find that my passport expires in july 2021, i.e. 2 months before my I-797 validity end date. I wanted to know if I still go through visa stamping process in May 2019, will my (A) Visa stamp, and (B) the I-94 at the port of entry have the end date of Sept 2021 (I-797 validity end date) or July 2021 (passport validity end date)?
If any of the two will have end date of July 2021 instead of sept 2021, will it reduce my work authorisation or US stay by those 2 months?

I know that Indian passport can only be renewed 12 months before its exipry date. So, if the above problem happens, my alternative would be to renew my passport in 2020 and then go for stamping.
Thank you for guiding me.

[VisaIssues86]

Your I-94 will only be given till your passport expiry date, you will have to renew your passport before it expires, and then go to the CBP to get this corrected, or you can also travel out of the country on your new passport, and they will extend the I-94 till sep 21