From: Arfrever Frehtes Taifersar Arahesis <Arfrever@Apache.Org>
Date: Mon, 23 Nov 2015 03:54:00 +0000
Subject: [PATCH 1/1] When UChar is defined as char16_t in ICU, then qtbase fails to detect ICU.

Build fails with following error:

ICU auto-detection... ()
x86_64-pc-linux-gnu-g++ -c -march=core2 -O2 -fno-ident \
 -frecord-gcc-switches -pipe -Wall -O2 -Wall -W -fPIC  -I. \
 -I/var/tmp/portage/dev-qt/qtcore-5.5.1/work/qtbase-opensource-src-5.5.1/mkspecs/linux-g++ -o icu.o icu.cpp
In file included from /usr/include/unicode/utypes.h:36:0,
                 from icu.cpp:34:
/usr/include/unicode/umachine.h:306:13: error: 'char16_t' does not name a type
     typedef char16_t UChar;
             ^
In file included from /usr/include/unicode/utypes.h:37:0,
                 from icu.cpp:34:
/usr/include/unicode/uversion.h:165:55: error: 'UChar' does not name a type
 u_versionFromUString(UVersionInfo versionArray, const UChar *versionString);
                                                       ^
...
Makefile:177: recipe for target 'icu.o' failed
gmake: *** [icu.o] Error 1
ICU disabled.
The ICU library support cannot be enabled.

This change isn't needed for new Qt versions, because c++11 is mandatory since 5.7.
Upstream desided not to merge this change into old branches, like 5.6.
Original patch was slightly modified to apply cleanly on Qt 5.6.3.

Fetch from: https://bugreports.qt.io/secure/attachment/52478/qtbase-5.5.1-icu.patch
Signed-off-by: Arfrever Frehtes Taifersar Arahesis <Arfrever@Apache.Org>
Signed-off-by: Andrey Skvortsov <andrej.skvortzov@gmail.com>

---
diff -purN qt5base-5.6.3.orig/config.tests/unix/compile.test qt5base-5.6.3/config.tests/unix/compile.test
--- qt5base-5.6.3.orig/config.tests/unix/compile.test	2019-08-11 00:35:33.181545706 +0300
+++ qt5base-5.6.3/config.tests/unix/compile.test	2017-09-06 15:13:54.000000000 +0300
@@ -47,7 +47,7 @@ while [ "$#" -gt 0 ]; do
         INC=`echo $PARAM | sed -e 's/^-I//'`
         INCLUDEPATH="$INCLUDEPATH \"$INC\""
         ;;
-    -f*|-D*)
+    -f*|-D*|-std=*)
         CFLAGS="$CFLAGS \"$PARAM\""
         CXXFLAGS="$CXXFLAGS \"$PARAM\""
         ;;
diff -purN qt5base-5.6.3.orig/configure qt5base-5.6.3/configure
--- qt5base-5.6.3.orig/configure	2019-08-11 00:57:45.488214036 +0300
+++ qt5base-5.6.3/configure	2017-09-06 15:13:54.000000000 +0300
@@ -5183,8 +5183,10 @@ fi
 
 # auto-detect libicu support
 if [ "$CFG_ICU" != "no" ]; then
-    if compileTest unix/icu "ICU"; then
+    QT_CXXFLAGS_ICU=`icu-config --cxxflags 2>/dev/null`
+    if compileTest unix/icu "ICU" $QT_CXXFLAGS_ICU; then
         [ "$CFG_ICU" = "auto" ] && CFG_ICU=yes
+        QMakeVar set QT_CXXFLAGS_ICU "$QT_CXXFLAGS_ICU"
     else
         if [ "$CFG_ICU" = "auto" ]; then
             CFG_ICU=no
diff -purN qt5base-5.6.3.orig/doc/Makefile qt5base-5.6.3/doc/Makefile
diff -purN qt5base-5.6.3.orig/src/corelib/tools/tools.pri qt5base-5.6.3/src/corelib/tools/tools.pri
--- qt5base-5.6.3.orig/src/corelib/tools/tools.pri	2019-08-11 00:45:45.073818635 +0300
+++ qt5base-5.6.3/src/corelib/tools/tools.pri	2017-09-06 15:13:54.000000000 +0300
@@ -169,6 +169,7 @@ contains(QT_CONFIG,icu) {
                tools/qcollator_icu.cpp \
                tools/qtimezoneprivate_icu.cpp
     DEFINES += QT_USE_ICU
+    QMAKE_CXXFLAGS += $$QT_CXXFLAGS_ICU
 } else: win32 {
     SOURCES += tools/qcollator_win.cpp
 } else: macx {