program size increse when use ParseFromArray for non-ordinary protobuf messages

[Dmitry Gorelov]

Hello!

I met a  problem of size increase of my program written in C++.

During investigation I came to a simple piece of code, incapsulated in a {} block, where:

- I create a protobuf message, fill it in with some dummy values.

- get size by calling msg.ByteSizeLong(),

- serialize msg to array of chars allocated to size  I got on previous step.

- Immediatelly I call ParseFromArray of another protobuf message of the same type, using same array and size as data source.

- And exit from the code block.

If the number of objects (either repeated or map<>) in the message is big enough, I see that the size of a program grows and never gets smaller.

If repeated the call of block 10 times, or more, the program size gets noticeable big.

I expect that the protobuf message objects do clear used memory at the moment when program exits the {} block from message destructor.

But this does not happen.