From 05af8bd4843001384335eb1ece22e8ca650e98c9 Mon Sep 17 00:00:00 2001
From: Luke Dashjr <luke-jr+git@utopios.org>
Date: Fri, 11 Dec 2020 02:13:14 +0000
Subject: [PATCH] GUI: If QWinTaskbarButton is missing, just build without it

---
 build-aux/m4/bitcoin_qt.m4 | 19 ++++++++++++++++---
 configure.ac               |  2 +-
 src/qt/bitcoingui.cpp      | 12 +++++++-----
 src/qt/bitcoingui.h        |  2 +-
 4 files changed, 25 insertions(+), 10 deletions(-)

diff --git a/build-aux/m4/bitcoin_qt.m4 b/build-aux/m4/bitcoin_qt.m4
index daac543448..ac1e90adda 100644
--- a/build-aux/m4/bitcoin_qt.m4
+++ b/build-aux/m4/bitcoin_qt.m4
@@ -273,6 +273,20 @@ AC_DEFUN([BITCOIN_QT_CONFIGURE],[
     AC_MSG_RESULT([$bitcoin_enable_qt])
   fi
 
+  AC_MSG_CHECKING([whether to build with QWinTaskbarProgress support])
+  BITCOIN_QT_CHECK([
+    if test "x$have_qt_winextras" != xyes; then
+      AC_MSG_RESULT([no, ${qt_lib_prefix}WinExtras $qt_version not found])
+    elif test "x$have_dwmapi" != xyes; then
+      AC_MSG_RESULT([no, dwmapi missing])
+    else
+      AC_MSG_RESULT([yes])
+      QT_INCLUDES="$QT_INCLUDES $QT_WINEXTRAS_CFLAGS"
+      QT_LIBS="$QT_LIBS $QT_WINEXTRAS_LIBS"
+      AC_DEFINE(BITCOIN_QT_WIN_TASKBAR, 1, [Define this symbol if building with QWinTaskbarProgress])
+    fi
+  ])
+
   AC_SUBST(QT_PIE_FLAGS)
   AC_SUBST(QT_INCLUDES)
   AC_SUBST(QT_LIBS)
@@ -398,10 +412,9 @@ AC_DEFUN([_BITCOIN_QT_FIND_LIBS],[
   BITCOIN_QT_CHECK([
     if test "x$TARGET_OS" = xwindows; then
       PKG_CHECK_MODULES([QT_WINEXTRAS], [${qt_lib_prefix}WinExtras $qt_version], [
-        QT_INCLUDES="$QT_INCLUDES $QT_WINEXTRAS_CFLAGS"
-        QT_LIBS="$QT_LIBS $QT_WINEXTRAS_LIBS"
+        have_qt_winextras=yes
       ],[
-        BITCOIN_QT_FAIL([${qt_lib_prefix}WinExtras $qt_version not found])
+        have_qt_winextras=no
       ])
     fi
   ])
diff --git a/configure.ac b/configure.ac
index 578487c488..266993cd71 100644
--- a/configure.ac
+++ b/configure.ac
@@ -699,7 +699,7 @@ case $host in
      AC_CHECK_LIB([ws2_32],   [WSAStartup],              [], [AC_MSG_ERROR([libws2_32 missing])])
      AC_CHECK_LIB([shlwapi],  [PathRemoveFileSpecW],     [], [AC_MSG_ERROR([libshlwapi missing])])
      AC_CHECK_LIB([iphlpapi], [GetAdaptersAddresses],    [], [AC_MSG_ERROR([libiphlpapi missing])])
-     AC_CHECK_LIB([dwmapi],   [main],                    [], [AC_MSG_ERROR([libdwmapi missing])])
+     AC_CHECK_LIB([dwmapi],   [main],                    [have_dwmapi=yes], [have_dwmapi=no])
 
      dnl -static is interpreted by libtool, where it has a different meaning.
      dnl In libtool-speak, it's -all-static.
diff --git a/src/qt/bitcoingui.cpp b/src/qt/bitcoingui.cpp
index 60cd3e6566..241495d2e6 100644
--- a/src/qt/bitcoingui.cpp
+++ b/src/qt/bitcoingui.cpp
@@ -28,7 +28,8 @@
 
 #ifdef Q_OS_MACOS
 #include <qt/macdockiconhandler.h>
-#elif defined Q_OS_WIN
+#endif
+#ifdef BITCOIN_QT_WIN_TASKBAR
 #include <QWinTaskbarButton>
 #include <QWinTaskbarProgress>
 #endif
@@ -223,7 +224,8 @@ BitcoinGUI::BitcoinGUI(interfaces::Node& node, const PlatformStyle *_platformSty
 
 #ifdef Q_OS_MACOS
     m_app_nap_inhibitor = new CAppNapInhibitor;
-#elif defined Q_OS_WIN
+#endif
+#ifdef BITCOIN_QT_WIN_TASKBAR
     m_taskbar_button = new QWinTaskbarButton(this);
 #endif
 
@@ -1133,7 +1135,7 @@ void BitcoinGUI::setNumBlocks(int count, const QDateTime& blockDate, double nVer
 
     tooltip = tr("Processed %n block(s) of transaction history.", "", count);
 
-#ifdef Q_OS_WIN
+#ifdef BITCOIN_QT_WIN_TASKBAR
     m_taskbar_button->setWindow(windowHandle());
     QWinTaskbarProgress* taskbar_progress = m_taskbar_button->progress();
 #endif
@@ -1153,7 +1155,7 @@ void BitcoinGUI::setNumBlocks(int count, const QDateTime& blockDate, double nVer
 
         progressBarLabel->setVisible(false);
         progressBar->setVisible(false);
-#ifdef Q_OS_WIN
+#ifdef BITCOIN_QT_WIN_TASKBAR
         taskbar_progress->setVisible(false);
 #endif
     }
@@ -1166,7 +1168,7 @@ void BitcoinGUI::setNumBlocks(int count, const QDateTime& blockDate, double nVer
         progressBar->setMaximum(1000000000);
         progressBar->setValue(nVerificationProgress * 1000000000.0 + 0.5);
         progressBar->setVisible(true);
-#ifdef Q_OS_WIN
+#ifdef BITCOIN_QT_WIN_TASKBAR
         taskbar_progress->setValue(qRound(nVerificationProgress * 100.0));
         taskbar_progress->setVisible(true);
 #endif
diff --git a/src/qt/bitcoingui.h b/src/qt/bitcoingui.h
index 449282c6dd..fdf1ecac0f 100644
--- a/src/qt/bitcoingui.h
+++ b/src/qt/bitcoingui.h
@@ -175,7 +175,7 @@ private:
     Notificator* notificator = nullptr;
     RPCConsole* rpcConsole = nullptr;
     HelpMessageDialog* helpMessageDialog = nullptr;
-#ifdef Q_OS_WIN
+#ifdef BITCOIN_QT_WIN_TASKBAR
     QWinTaskbarButton* m_taskbar_button = nullptr;
 #endif
     ModalOverlay* modalOverlay = nullptr;