What is the case of «عُمَرَ» in «مَرَرْتُ بِعُمَرَ»?

Causes of Diptote Status — ʿAdl and Waṣf

• Accusative because fatḥa appears
• Genitive after bi-, marked by fatḥa
• Nominative subject
• Indeclinable on fatḥ