If a marker file indicates that an installer has been downloaded and verified
and is ready to install, but that installer file does not exist, log it and
revert to checking for update.
Also add logging to every code path that can remove the installer explicitly,
in case the missing installer is actually being killed off by some weird
sequence of state-machine transitions.
Now LLProcess explicitly requests APR to limit the handles passed to any child
process, instead of wantonly passing whatever happens to be lying around the
parent process at the time.
This requires the latest APR build.
Also revert LLUpdateDownloader::Implementation::mDownloadStream to llofstream
(as in rev 1878a57aebd7) instead of apr_file_t*. Using APR for that file was a
Band-Aid -- a single whacked mole -- for the problem more systemically
addressed by apr_procattr_constrain_handle_set().
This handles the case when the target file doesn't exist, just as APR_TRUNCATE
handles the case when it does.
Strengthen error checks concerning downloaded installer file from
ll_apr_warn_status() to ll_apr_assert_status(). Failing to recognize (e.g.)
failure to open that file only leads to mysterious crashes down the road; this
removes the mystery.
On Windows, calling CreateProcess(bInheritHandles=FALSE) is the wrong idea. In
that case, CreateProcess() passes NO handles -- even the files you've
explicitly designated as the child's stdin, stdout, stderr in the STARTUPINFO
struct! Remove LLProcess code to tweak bInheritHandles; we should also remove
the corresponding (useless) APR extension.
Instead, given that the Windows file-locking problem we've observed is
specific to the viewer installer .exe file downloaded by the background
updater logic, use APR file I/O for that specific file. Empirically, both
llofstream and std::ofstream seem to make the open file handle inheritable;
but apr_file_open() documentation says: "By default, the returned file
descriptor will not be inherited by child processes created by
apr_proc_create()." And indeed, it does appear to sidestep the locking problem.
Nat Goodspeed