QGuiApplication: invert meaning of qt_is_gui_used

The default value was true, which is non-zero, forcing the variable
out of the BSS and into the DATA segment.

Fix by inverting the meaning so the default value can be false.

Since qt_is_gui_unused sounds a bit complicated, however, take a cue
from the variable's only writer and rename it qt_is_tty_app.

Pick-to: 6.3
Change-Id: I198e9786f7e71178d69fecb5179287bf39b3a1d6
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@qt.io>
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>

1 files changed, 1 insertions, 1 deletions

diff --git a/src/gui/kernel/qguiapplication.cpp b/src/gui/kernel/qguiapplication.cpp
index 9f85d3ae47..ecdf2c6959 100644
--- a/src/gui/kernel/qguiapplication.cpp
+++ b/src/gui/kernel/qguiapplication.cpp
@@ -138,7 +138,7 @@ QT_BEGIN_NAMESPACE
     }
 
 Q_CORE_EXPORT void qt_call_post_routines();
-Q_GUI_EXPORT bool qt_is_gui_used = true;
+Q_GUI_EXPORT bool qt_is_tty_app = false;
 
 Qt::MouseButtons QGuiApplicationPrivate::mouse_buttons = Qt::NoButton;
 Qt::KeyboardModifiers QGuiApplicationPrivate::modifier_buttons = Qt::NoModifier;