Android: fix GUI not loading on Qt 5.15 #504

Qt 5.14 introduced certain breaking changes to the way it parses AndroidManifest.xml metadata.

This PR also adds an explicit QAndroidPlatformIntegrationPlugin import to bitcoin.cpp (in line with other platforms). I'm not sure why Android GUI worked without this before but it certainly doesn't on Qt 5.15.

We could do without Q_IMPORT_PLUGIN before because we were manually pulling a JNI_Onload function to the linkage.

cc @hebasto

Concept ACK.

https://cirrus-ci.com/task/5550307582148608:

ld: error: duplicate symbol: JNI_OnLoad
>>> defined at qjnionload.cpp
>>>            qjnionload.o:(JNI_OnLoad) in archive /tmp/cirrus-ci-build/depends/aarch64-linux-android/lib/libQt5Core_arm64-v8a.a
>>> defined at androidjnimain.cpp
>>>            androidjnimain.o:(.text.JNI_OnLoad+0x0) in archive /tmp/cirrus-ci-build/depends/aarch64-linux-android/plugins/platforms/libplugins_platforms_qtforandroid_arm64-v8a.a
clang-12: error: linker command failed with exit code 1 (use -v to see invocation)
make[2]: *** [Makefile:6462: qt/test/test_bitcoin-qt] Error 1

Tested f2f924e919b110cc5f33aac4caa4b296991d3706 (configured with --disable-tests):

I've updated the PR description to explain why we could get away with not using Q_IMPORT_PLUGIN.

Broken qt_test linkage in CI is related. I'm trying to figure out a nice way to fix this.

I've updated the PR description to explain why we could get away with not using Q_IMPORT_PLUGIN.

Broken qt_test linkage in CI is related. I'm trying to figure out a nice way to fix this.

The following patch fixes link error:

--- a/build-aux/m4/bitcoin_qt.m4
+++ b/build-aux/m4/bitcoin_qt.m4
@@ -162,6 +162,7 @@ AC_DEFUN([BITCOIN_QT_CONFIGURE],[
       AC_DEFINE([QT_QPA_PLATFORM_COCOA], [1], [Define this symbol if the qt platform is cocoa])
     elif test "$TARGET_OS" = "android"; then
       QT_LIBS="-Wl,--export-dynamic,--undefined=JNI_OnLoad -lplugins_platforms_qtforandroid_$ANDROID_ARCH -ljnigraphics -landroid -lqtfreetype_$ANDROID_ARCH $QT_LIBS"
+      QT_TEST_LIBS="-Wl,--export-dynamic,--undefined=JNI_OnLoad -lplugins_platforms_qtforandroid_$ANDROID_ARCH -ljnigraphics -landroid -lqtfreetype_$ANDROID_ARCH $QT_TEST_LIBS"
       AC_DEFINE([QT_QPA_PLATFORM_ANDROID], [1], [Define this symbol if the qt platform is android])
     fi
   fi

Not sure if it is optimal though.

UPDATE: See a more preferable patch in #504 (comment).

I've updated the PR description to explain why we could get away with not using Q_IMPORT_PLUGIN. Broken qt_test linkage in CI is related. I'm trying to figure out a nice way to fix this.

The following patch fixes link error:

--- a/build-aux/m4/bitcoin_qt.m4
+++ b/build-aux/m4/bitcoin_qt.m4
@@ -162,6 +162,7 @@ AC_DEFUN([BITCOIN_QT_CONFIGURE],[
       AC_DEFINE([QT_QPA_PLATFORM_COCOA], [1], [Define this symbol if the qt platform is cocoa])
     elif test "$TARGET_OS" = "android"; then
       QT_LIBS="-Wl,--export-dynamic,--undefined=JNI_OnLoad -lplugins_platforms_qtforandroid_$ANDROID_ARCH -ljnigraphics -landroid -lqtfreetype_$ANDROID_ARCH $QT_LIBS"
+      QT_TEST_LIBS="-Wl,--export-dynamic,--undefined=JNI_OnLoad -lplugins_platforms_qtforandroid_$ANDROID_ARCH -ljnigraphics -landroid -lqtfreetype_$ANDROID_ARCH $QT_TEST_LIBS"
       AC_DEFINE([QT_QPA_PLATFORM_ANDROID], [1], [Define this symbol if the qt platform is android])
     fi
   fi

Not sure if it is optimal though.

A more optimal suggestion:

--- a/src/Makefile.qttest.include
+++ b/src/Makefile.qttest.include
@@ -52,7 +52,7 @@ if ENABLE_ZMQ
 qt_test_test_bitcoin_qt_LDADD += $(LIBBITCOIN_ZMQ) $(ZMQ_LIBS)
 endif
 qt_test_test_bitcoin_qt_LDADD += $(LIBBITCOIN_CLI) $(LIBBITCOIN_COMMON) $(LIBBITCOIN_UTIL) $(LIBBITCOIN_CONSENSUS) $(LIBBITCOIN_CRYPTO) $(LIBUNIVALUE) $(LIBLEVELDB) \
-  $(LIBLEVELDB_SSE42) $(LIBMEMENV) $(BOOST_LIBS) $(QT_DBUS_LIBS) $(QT_TEST_LIBS) $(QT_LIBS) \
+  $(LIBLEVELDB_SSE42) $(LIBMEMENV) $(BOOST_LIBS) $(QT_LIBS) $(QT_DBUS_LIBS) $(QT_TEST_LIBS) \
   $(QR_LIBS) $(BDB_LIBS) $(MINIUPNPC_LIBS) $(NATPMP_LIBS) $(LIBSECP256K1) \
   $(EVENT_PTHREADS_LIBS) $(EVENT_LIBS) $(SQLITE_LIBS)
 qt_test_test_bitcoin_qt_LDFLAGS = $(RELDFLAGS) $(AM_LDFLAGS) $(QT_LDFLAGS) $(LIBTOOL_APP_LDFLAGS) $(PTHREAD_FLAGS)

UPDATE: Suggesting to move this PR into the main repo as it touches the code outside the src/qt.

UPDATE: Suggesting to move this PR into the main repo as it touches the code outside the src/qt.

Is there a nice way to do this? I'd like to preserve comments and stuff.

@icota

UPDATE: Suggesting to move this PR into the main repo as it touches the code outside the src/qt.

Is there a nice way to do this?

No, there is not, unfortunately.

I'd like to preserve comments and stuff.

A link to this PR in the OP will work fine.

Continued in https://github.com/bitcoin/bitcoin/pull/23757