build: convert "echo" usage into a patch in qt package

depends/packages/qt.mk

@@ -12,6 +12,7 @@ $(package)_patches=fix_qt_pkgconfig.patch mac-qmake.conf fix_configure_mac.patch
 $(package)_patches+= fix_rcc_determinism.patch fix_riscv64_arch.patch xkb-default.patch no-xlib.patch
 $(package)_patches+= fix_android_qmake_conf.patch fix_android_jni_static.patch dont_hardcode_pwd.patch
 $(package)_patches+= freetype_back_compat.patch drop_lrelease_dependency.patch fix_powerpc_libpng.patch
+$(package)_patches+= fix_mingw_cross_compile.patch
 
 # Update OSX_QT_TRANSLATIONS when this is updated
 $(package)_qttranslations_file_name=qttranslations-$($(package)_suffix)
@@ -217,8 +218,7 @@ define $(package)_preprocess_cmds
   echo "!host_build: QMAKE_LFLAGS     += $($(package)_ldflags)" >> qtbase/mkspecs/common/gcc-base.conf && \
   patch -p1 -i $($(package)_patch_dir)/fix_riscv64_arch.patch &&\
   patch -p1 -i $($(package)_patch_dir)/no-xlib.patch &&\
-  echo "QMAKE_LINK_OBJECT_MAX = 10" >> qtbase/mkspecs/win32-g++/qmake.conf &&\
-  echo "QMAKE_LINK_OBJECT_SCRIPT = object_script" >> qtbase/mkspecs/win32-g++/qmake.conf &&\
+  patch -p1 -i $($(package)_patch_dir)/fix_mingw_cross_compile.patch && \
   sed -i.old "s|QMAKE_CFLAGS           += |!host_build: QMAKE_CFLAGS            = $($(package)_cflags) $($(package)_cppflags) |" qtbase/mkspecs/win32-g++/qmake.conf && \
   sed -i.old "s|QMAKE_CXXFLAGS         += |!host_build: QMAKE_CXXFLAGS            = $($(package)_cxxflags) $($(package)_cppflags) |" qtbase/mkspecs/win32-g++/qmake.conf && \
   sed -i.old "0,/^QMAKE_LFLAGS_/s|^QMAKE_LFLAGS_|!host_build: QMAKE_LFLAGS            = $($(package)_ldflags)\n&|" qtbase/mkspecs/win32-g++/qmake.conf && \

depends/patches/qt/fix_mingw_cross_compile.patch

@@ -0,0 +1,25 @@
+commit 5a992a549adfe5a587bbcd6cd2b2cee47d236e27
+Author: fanquake <fanquake@gmail.com>
+Date:   Fri Sep 4 08:13:44 2020 +0800
+
+    Work around broken mingw cross-compilation
+
+    See upstream issues:
+    https://bugreports.qt.io/browse/QTBUG-63637
+    https://bugreports.qt.io/browse/QTBUG-63659
+    https://codereview.qt-project.org/q/8bebded9
+
+    We should be able to drop this once we are building qt 5.10.1 or later.
+
+    Added in #12971.
+
+diff --git a/qtbase/mkspecs/win32-g++/qmake.conf b/qtbase/mkspecs/win32-g++/qmake.conf
+index e071a0d1..ad229b10 100644
+--- a/qtbase/mkspecs/win32-g++/qmake.conf
++++ b/qtbase/mkspecs/win32-g++/qmake.conf
+@@ -87,3 +87,5 @@ QMAKE_NM                = $${CROSS_COMPILE}nm -P
+ include(../common/angle.conf)
+
+ load(qt_config)
++QMAKE_LINK_OBJECT_MAX = 10
++QMAKE_LINK_OBJECT_SCRIPT = object_script