PrivilegesRequired=lowest makes Inno Setup "always run in non
administrative install mode" — the launching token is irrelevant. So a
copy that ended up in C:\Program Files, which the destination page still
lets an elevated wizard run pick, is registered under HKCU while living
somewhere an ordinary process cannot write. UsePreviousAppDir then aims
every later run straight back at that directory.
WinSparkle launches the downloaded installer with plain ShellExecuteEx
and no verb, so nothing along the in-app update path ever asks for
elevation: the silent installer starts, cannot replace a single file, and
the only way out was to quit Plezy, fetch the installer by hand and pick
"Run as administrator". Inno's own PrivilegesRequiredOverridesAllowed
plus UsePreviousPrivileges does not help here, because it reads the
recorded install mode — which is exactly the non-administrative one that
cannot write.
Decide on write access instead. InitializeSetup probes the registered
install directory and, when it is not writable, relaunches setup through
ShellExec 'runas' pinned to that directory with /ALLUSERS, so the update
lands in place instead of forking a second per-user copy. The relaunch
carries a guard parameter and drops any conflicting mode override, and a
refused UAC prompt now explains itself and points at the releases page
rather than failing mutely. A machine-wide install that takes over a
per-user directory also clears the stale uninstall entry and Start Menu
group that would otherwise list Plezy twice in Apps & Features.
Fresh installs are unchanged: still per-user, still no prompt. Only
commandline is added to PrivilegesRequiredOverridesAllowed, since
allowing dialog would make a silent install with no previous copy stop
for the install-mode question — which is how winget installs.
The script carried two near-identical copies of the whole .iss, one per
architecture shape, so both would have needed this code. Collapse them
into one template parameterised by architecture, add -EmitScriptOnly to
generate the .iss without 7-Zip or Inno Setup, and guard the contract
with check_windows_installer.py so the elevation path, the single-source
AppId and the winget marker cannot rot.
close#1705
edde746