PNP switching circuit - How it will be correct?
You are correct in saying that this configuration is "theoretically wrong". 

BJTs are capable of delivering their maximal current in one particular configuration (Forward-Active). For PNP transistors, this configuration requires: \$V_{EB} \approx 0.7V\$, and \$V_B&gt;V_C\$.

I don't know what TRIAC in your schematics means. Based on the value of this voltage and the load following the Emitter, your PNP will be either in Reverse-Active or Cutoff region of operation. While there is still some current the transistor can sustain when reverse biased (it may even suffice to drive seven-segment or similar low current loads), this is not a good idea to employ this approach.

As you said: "The supply should be connected in emitter for PNP for driving". Do it then.