Fix detection of private Qt6 headers

The gui-private is a separate module. Private Qt6 GUI headers
are currently used only with the Windows backend. However they
are needed to port to Qt6 all functionality that was depending
on the -extras modules. For example, all code guarded by the
macro HAVE_QT5_X11_EXTRAS has to be audited and properly replaced
by Qt6 code. See for example 771f30e9 and 17b24cf4.

diff --git a/config/qt.m4 b/config/qt.m4
index b33be23ebaf3fce7bce096b5ef9d1a9245c44623..7e7ffd6df2af62275fd72a873f351b5fd31b27a1 100644 (file)
--- a/config/qt.m4
+++ b/config/qt.m4
@@ -414,7 +414,8 @@ EOF1
 QMAKE_EXTRA_VARIABLES = MISSING
 qtHaveModule(core)             {QT += core} else {MISSING += core}
 qtHaveModule(concurrent)       {QT += concurrent} else {MISSING += concurrent}
-qtHaveModule(gui)              {QT += gui gui-private} else {MISSING += gui}
+qtHaveModule(gui)              {QT += gui} else {MISSING += gui}
+qtHaveModule(gui-private)      {QT += gui-private} else {MISSING += gui-private}
 qtHaveModule(svg)              {QT += svg} else {MISSING += svg}
 qtHaveModule(svgwidgets)       {QT += svgwidgets} else {MISSING += svgwidgets}
 qtHaveModule(widgets)          {QT += widgets} else {MISSING += widgets}