edb-postgres.exe has encountered a problem on windows

Problem:
========

On windows when we run edb-postgres.exe without any command line args, its getting crash or its showing error into Application logs of Event Viewer.

Analysis:
==========

For any stderr we call the write_stderr() and write_stderr() calls the write_console() for stderr. Now here write_console() using the palloc() internally, which require the CurrentMemoryContext.

At the startup CurrentMemoryContext will be NULL, so palloc again calling write_stderr(). So recursion has been started and its ending up with exception.

Call stack for palloc() is:

main() -> check_root() -> write_stderr() -> write_console() -> pgwin32_toUTF16() -> palloc()

Fix:
=====

Earlier  we used to call vfprintf() for windows stderr, which is now replaced with write_console().
So to avoid the exception now, I added condition for CurrentMemoryContext into write_stderr().

PFA patch to fix the same.

Regards,
Rushabh Lathia
EnterpriseDB, The Enterprise PostgreSQL company.