Help/litehtml: Fix litehtml build on Windows and with GCC 5.3

GCC 5.3 doesn't want to convert char* literals to QString sometimes, and
for MSVC conversions litehtml::tstring/tchar_t <->
QString::fromStdString/QString fails because the former was wstring and
wchar
Also position independent code is needed on Linux

Change-Id: Iec8dd0d9d38a07cd1c4db49c9edf10e3d1d5b156
Reviewed-by: Tobias Hunger <tobias.hunger@qt.io>

src/plugins/help/qlitehtml/CMakeLists.txt

@@ -2,26 +2,32 @@ cmake_minimum_required(VERSION 3.9)
 
 project(QLiteHtml)
 
-set(CMAKE_AUTOMOC ON)
-set(CMAKE_AUTORCC ON)
-set(CMAKE_AUTOUIC ON)
-set(CMAKE_CXX_STANDARD 14)
-
 if (EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/litehtml/CMakeLists.txt)
+    set(ORIG_FPIC ${CMAKE_POSITION_INDEPENDENT_CODE})
     set(ORIG_CMAKE_BUILD_TYPE ${CMAKE_BUILD_TYPE})
     if (CMAKE_BUILD_TYPE STREQUAL "Debug" OR CMAKE_BUILD_TYPE STREQUAL "RelWithDebInfo")
       set(CMAKE_BUILD_TYPE "RelWithDebInfo")
     else()
       set(CMAKE_BUILD_TYPE "Release")
     endif()
+    if (WIN32)
+      set(LITEHTML_UTF8 ON)
+    endif()
+    set(CMAKE_POSITION_INDEPENDENT_CODE ON)
     add_subdirectory(litehtml)
     set(CMAKE_BUILD_TYPE ${ORIG_CMAKE_BUILD_TYPE})
+    set(CMAKE_POSITION_INDEPENDENT_CODE "${ORIG_FPIC}")
 else()
     find_package(litehtml REQUIRED)
 endif()
 
 find_package(Qt5 COMPONENTS Widgets REQUIRED)
 
+set(CMAKE_AUTOMOC ON)
+set(CMAKE_AUTORCC ON)
+set(CMAKE_AUTOUIC ON)
+set(CMAKE_CXX_STANDARD 14)
+
 add_library(qlitehtml STATIC
   container_qpainter.cpp container_qpainter.h
   qlitehtmlwidget.cpp qlitehtmlwidget.h
@@ -29,3 +35,4 @@ add_library(qlitehtml STATIC
 
 target_include_directories(qlitehtml PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})
 target_link_libraries(qlitehtml PRIVATE Qt5::Widgets litehtml)
+set_target_properties(qlitehtml PROPERTIES POSITION_INDEPENDENT_CODE ON)

src/plugins/help/qlitehtml/container_qpainter.cpp

@@ -1232,19 +1232,19 @@ QPixmap DocumentContainer::getPixmap(const QString &imageUrl, const QString &bas
 QString DocumentContainer::serifFont() const
 {
     // TODO make configurable
-    return "Times New Roman";
+    return {"Times New Roman"};
 }
 
 QString DocumentContainer::sansSerifFont() const
 {
     // TODO make configurable
-    return "Arial";
+    return {"Arial"};
 }
 
 QString DocumentContainer::monospaceFont() const
 {
     // TODO make configurable
-    return "Courier";
+    return {"Courier"};
 }
 
 QUrl DocumentContainer::resolveUrl(const QString &url, const QString &baseUrl) const

src/plugins/help/qlitehtml/qlitehtml.pri

@@ -11,10 +11,13 @@ exists($$PWD/litehtml/CMakeLists.txt) {
         system("$$sprintf($$QMAKE_MKDIR_CMD, $$shell_path($${LITEHTML_BUILD_PATH}))")
 
         macos: CMAKE_DEPLOYMENT_TARGET = -DCMAKE_OSX_DEPLOYMENT_TARGET=$${QMAKE_MACOSX_DEPLOYMENT_TARGET}
+        win32: LITEHTML_UTF8 = -DLITEHTML_UTF8=ON
         LITEHTML_CMAKE_CMD = \
             "$$QMAKE_CD $$system_quote($$shell_path($${LITEHTML_BUILD_PATH})) && \
              cmake -DCMAKE_BUILD_TYPE=$$BUILD_TYPE \
                    -DCMAKE_INSTALL_PREFIX=$$system_quote($$shell_path($${LITEHTML_INSTALL_PATH})) \
+                   -DCMAKE_POSITION_INDEPENDENT_CODE=ON \
+                   $$LITEHTML_UTF8 \
                    $$CMAKE_DEPLOYMENT_TARGET \
                    $$system_quote($$shell_path($${LITEHTML_SOURCE_PATH}))"
         message("$${LITEHTML_CMAKE_CMD}")