cmdutil: hide child window created by win32 spawndetached() Hiding the child process window is not strictly necessary but it avoids opening an empty shell window when running hg serve as well as a task in the task bar. The window is hidden after the process is already started causing a single flicker.

Find right hg command for detached process On Windows, Mercurial can be run from the python script of from a frozen executable. In the first case, we have to call the python interpreter since the script is not executable. Frozen executable can be called directly. Fix 3/3 for issue421

cmdutil: replace unix pipe handshake with file lock The pipe handshake cannot be implemented with Windows detached process, which disables handle inheritance. Fix 2/3 for issue421

serve: add and use portable spawnvp replacement There is no standard python command to really detach a process under Windows. Instead we use the low level API wrapped by subprocess module with all necessary options to avoid any kind of context inheritance. Unfortunately, this version still opens a new window for the child process. The following have been tried: - os.spawnv(os.P_NOWAIT): works but the child process is killed when parent console terminates. - os.spawnv(os.P_DETACH): works on python25, hang on python26 when writing to the hgweb output socket. - subprocess.CreateProcess() hack without shell mode: similar to os.spawnv(os.P_DETACH). Fix 1/3 for issue421