fix: std C++17 case. patch: USE_UPNP=- as default. remove: USE_FORCE_STD_17=1

Author: IamLupo

README.md

@@ -141,14 +141,14 @@ cd DigitalNote
 
 With UPNP:
 ```
-qmake -qt=qt5 DigitalNote.daemon.pro USE_FORCE_STD_17=1
+qmake -qt=qt5 DigitalNote.daemon.pro USE_UPNP=1
 make -j 4
 sudo cp -r DigitalNoted /usr/local/bin/DigitalNoted
 ```
 
 **Recommended Without** UPNP:
 ```
-qmake -qt=qt5 DigitalNote.daemon.pro USE_FORCE_STD_17=1 USE_UPNP=-
+qmake -qt=qt5 DigitalNote.daemon.pro USE_UPNP=-
 make -j 4
 sudo cp -r DigitalNoted /usr/local/bin/DigitalNoted
 ```
@@ -165,13 +165,13 @@ export BDB_LIB_PATH="/usr/local/BerkeleyDB.6.2/lib"
 
 With UPNP:
 ```
-qmake -qt=qt5 DigitalNote.app.pro USE_FORCE_STD_17=1 USE_UPNP=- USE_DBUS=1 USE_QRCODE=1
+qmake -qt=qt5 DigitalNote.app.pro USE_DBUS=1 USE_QRCODE=1
 make -j 4
 ```
 
 **Recommended Without** UPNP:
 ```
-qmake -qt=qt5 DigitalNote.app.pro USE_FORCE_STD_17=1 USE_UPNP=- USE_DBUS=1 USE_QRCODE=1
+qmake -qt=qt5 DigitalNote.app.pro USE_DBUS=1 USE_QRCODE=1
 make -j 4
 ```
 

include/compiler_settings.pri

@@ -1,6 +1,8 @@
 CONFIG += strict_c++
 CONFIG += c++17
 
+include(fix_std_cxx_17.pri)
+
 QMAKE_CXXFLAGS = 
 
 QMAKE_CXXFLAGS_WARN_ON = -fdiagnostics-show-option

include/fix_std_cxx_17.pri

@@ -0,0 +1,15 @@
+## can be used with Qt 5.12 and later.
+## For Qt 5.11 and earlier, it is not a recognized QMake flag and you have to get your hands a bit dirty.
+##
+## Reference: https://stackoverflow.com/questions/46610996/cant-use-c17-features-using-g-7-2-in-qtcreator
+
+
+lessThan($$QT_MAJOR_VERSION, 5)
+{
+	QMAKE_CXXFLAGS += -std=c++17
+}
+
+isEqual($$QT_MINOR_VERSION, 5) | lessThan($$QT_MINOR_VERSION, 12)
+{
+	QMAKE_CXXFLAGS += -std=c++17
+}

include/libs/miniupnpc.pri

@@ -3,9 +3,9 @@
 #  or: qmake "USE_UPNP=-" (not supported)
 # miniupnpc (http://miniupnp.free.fr/files/) must be installed for support
 
-contains(USE_UPNP, -) {
-	message(Building without UPNP support)
-} else {
+contains(USE_UPNP, 1) {
+	message(Building UPNP support)
+	
 	win32 {
 		exists($${DIGITALNOTE_LIB_MINIUPNP_DIR}/libminiupnpc.a) {
 			message("found MiniUPNP lib")
@@ -36,4 +36,6 @@ contains(USE_UPNP, -) {
 
 	DEFINES += MINIUPNP_STATICLIB
 	DEFINES += USE_UPNP
+} else {
+	message(Building without UPNP support)
 }

include/options/use_force_std.pri

@@ -1,7 +1,3 @@
-## can be used with Qt 5.12 and later.
-## For Qt 5.11 and earlier, it is not a recognized QMake flag and you have to get your hands a bit dirty.
-##
-## Reference: https://stackoverflow.com/questions/46610996/cant-use-c17-features-using-g-7-2-in-qtcreator
 
 contains(USE_FORCE_STD_17, 1) {
 	QMAKE_CXXFLAGS += -std=c++17