Ardour translations and GUI string formatting only depends on the C locale.
Modifying the C++ locale may produce erratic results on various systems
(in particular OSX and macOS) and cause incompatibilies with plugins.
GTK events are still handled while un/loading a session (e.g display
"Loading" message or showing the splash triggers an event-loop run).
Global canvas elements (e.g. Rulers) may respond to session-specific
actions.
Since 5.8-245-g3e43585fa, a response hides the dialog Window
in ArdourDialog::on_response (to prevent dialogs windows staying
around unresponsively while Ardour does background work).
This logic does not apply to Dialog Windows which implement
ProgressReporter or support dialog responses other than OK, Close.
The numeric formatting is equivalent. Even though this string is being used in
the UI as a label I think this is another case where we don't want a localized
numeric string, which would only be relevant with a track count >=1000.
The numeric formatting is equivalent. The string is being used in a label so it
could be argued that we want localized numeric formatting in this case, but as
it is only relevant if we have >=1000 meter strip keep it the same for now.
The C++ global locale is currently set to LC_NUMERIC=C by the first instance of
LocaleGuard so this change means numeric formatting is equivalent.
As the string is being used to construct a label, perhaps we do want to
generate localized numeric formatting in this case. Anyway keep it the same for
now.
string_compose uses std::ostream/stringstream which will insert thousands
separators in some locales. This was not a problem when LocaleGuard set the
global C++ locale to "C"
std::ostream/stringstream will use the current locale to determine the numeric
formatting. If the locale uses grouping then thousands separators will be
inserted in the output which produces an invalid color string in
UIConfiguration::reset_gtk_theme() and when converting colors to strings in
UIConfiguration::store_color_theme()
This has not been a problem so far because it appears that LocaleGuard does not
reset the LC_NUMERIC value for the global C++ locale. So if a LocaleGuard is
created at any time before these functions are called(even if it goes out of
scope) the numeric formatting used by std::streams will use the "C" locale
formatting facets.