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.

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>
(cherry picked from commit 961f5a6fa22b338c975d81c959c502322fdb64af)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

4 files changed, 9 insertions, 9 deletions

diff --git a/src/gui/kernel/qguiapplication.cpp b/src/gui/kernel/qguiapplication.cpp
index d764d3a457..86034865d8 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;
diff --git a/src/gui/text/qfont.cpp b/src/gui/text/qfont.cpp
index ae0c495dcf..f663ac56fd 100644
--- a/src/gui/text/qfont.cpp
+++ b/src/gui/text/qfont.cpp
@@ -136,14 +136,14 @@ bool QFontDef::exactMatch(const QFontDef &other) const
        );
 }
 
-extern bool qt_is_gui_used;
+extern bool qt_is_tty_app;
 
 Q_GUI_EXPORT int qt_defaultDpiX()
 {
     if (QCoreApplication::instance()->testAttribute(Qt::AA_Use96Dpi))
         return 96;
 
-    if (!qt_is_gui_used)
+    if (qt_is_tty_app)
         return 75;
 
     if (const QScreen *screen = QGuiApplication::primaryScreen())
@@ -158,7 +158,7 @@ Q_GUI_EXPORT int qt_defaultDpiY()
     if (QCoreApplication::instance()->testAttribute(Qt::AA_Use96Dpi))
         return 96;
 
-    if (!qt_is_gui_used)
+    if (qt_is_tty_app)
         return 75;
 
     if (const QScreen *screen = QGuiApplication::primaryScreen())
diff --git a/src/widgets/kernel/qapplication.cpp b/src/widgets/kernel/qapplication.cpp
index 62870a25b7..8485fb8771 100644
--- a/src/widgets/kernel/qapplication.cpp
+++ b/src/widgets/kernel/qapplication.cpp
@@ -388,7 +388,7 @@ void QApplicationPrivate::process_cmdline()
         styleOverride = QString::fromLocal8Bit(qgetenv("QT_STYLE_OVERRIDE"));
 
     // process platform-indep command line
-    if (!qt_is_gui_used || !argc)
+    if (qt_is_tty_app || !argc)
         return;
 
     int i, j;
@@ -496,7 +496,7 @@ void QApplicationPrivate::init()
 
     initResources();
 
-    qt_is_gui_used = (application_type != QApplicationPrivate::Tty);
+    qt_is_tty_app = (application_type == QApplicationPrivate::Tty);
     process_cmdline();
 
     // Must be called before initialize()
@@ -559,7 +559,7 @@ void QApplicationPrivate::initialize()
     if (qEnvironmentVariableIntValue("QT_USE_NATIVE_WINDOWS") > 0)
         QCoreApplication::setAttribute(Qt::AA_NativeWindows);
 
-    if (qt_is_gui_used)
+    if (!qt_is_tty_app)
         initializeMultitouch();
 
     if (QGuiApplication::desktopSettingsAware())
@@ -719,7 +719,7 @@ QApplication::~QApplication()
     QApplicationPrivate::app_style = nullptr;
 
 #if QT_CONFIG(draganddrop)
-    if (qt_is_gui_used)
+    if (!qt_is_tty_app)
         delete QDragManager::self();
 #endif
 
diff --git a/src/widgets/kernel/qapplication_p.h b/src/widgets/kernel/qapplication_p.h
index 155081fd79..0f86269332 100644
--- a/src/widgets/kernel/qapplication_p.h
+++ b/src/widgets/kernel/qapplication_p.h
@@ -86,7 +86,7 @@ class QPointingDevice;
 class QGestureManager;
 #endif
 
-extern Q_GUI_EXPORT bool qt_is_gui_used;
+extern Q_GUI_EXPORT bool qt_is_tty_app;
 #ifndef QT_NO_CLIPBOARD
 extern QClipboard *qt_clipboard;
 #endif