Make a modified copy of qrc file for VPATH builds

Author: luke-jr

src/Makefile.qt.include

@@ -102,6 +102,7 @@ QT_MOC = \
 
 QT_QRC_CPP = qt/qrc_bitcoin.cpp
 QT_QRC = qt/bitcoin.qrc
+QT_QRC_BUILD = qt/qrc_bitcoin_build.qrc
 QT_QRC_LOCALE_CPP = qt/qrc_bitcoin_locale.cpp
 QT_QRC_LOCALE = qt/bitcoin_locale.qrc
 
@@ -379,11 +380,14 @@ $(QT_QRC_LOCALE_CPP): $(QT_QRC_LOCALE) $(QT_QM)
 	$(AM_V_GEN) QT_SELECT=$(QT_SELECT) $(RCC) -name bitcoin_locale --format-version 1 $(@D)/temp_$(<F) > $@
 	@rm $(@D)/temp_$(<F)
 
-$(QT_QRC_CPP): $(QT_QRC) $(QT_FORMS_H) $(QT_RES_FONTS) $(QT_RES_ICONS) $(QT_RES_ANIMATION)
+$(QT_QRC_BUILD): $(QT_QRC)
+	$(SED) -e 's:\(res\/\(icons\|animation\|fonts\)/\):$(abs_srcdir)/qt/\1:' <"$<" >"$@"
+
+$(QT_QRC_CPP): $(QT_QRC_BUILD) $(QT_FORMS_H) $(QT_RES_FONTS) $(QT_RES_ICONS) $(QT_RES_ANIMATION)
 	@test -f $(RCC) || (echo "rcc $(RCC) not found, but is required for generating qrc cpp files"; exit 1)
 	$(AM_V_GEN) QT_SELECT=$(QT_SELECT) $(RCC) -name bitcoin --format-version 1 $< > $@
 
-CLEAN_QT = $(nodist_qt_libbitcoinqt_a_SOURCES) $(QT_QM) $(QT_FORMS_H) qt/*.gcda qt/*.gcno qt/temp_bitcoin_locale.qrc
+CLEAN_QT = $(nodist_qt_libbitcoinqt_a_SOURCES) $(QT_QM) $(QT_FORMS_H) qt/*.gcda qt/*.gcno qt/temp_bitcoin_locale.qrc $(QT_QRC_BUILD)
 
 CLEANFILES += $(CLEAN_QT)