Merge bitcoin#15393: build: Bump minimum Qt version to 5.5.1

fd46c4c Bump minimum Qt version to 5.5.1 (Sjors Provoost)

Pull request description:

  Fixes bitcoin#13478

  Compiled and lightly tested on 10.14.3 against QT 5.12.0.

Tree-SHA512: 6890331969bbf4c66dc0993b8817b1f0831d008f5863554e9c09a38f4700260b84044ff961664c377decc9fb8300e3543c267f935ec64fbc97b20f8fb396247a
(cherry picked from commit 3b33cbc)

# Conflicts:
#	build-aux/m4/bitcoin_qt.m4
#	doc/dependencies.md
#	src/qt/test/apptests.cpp
#	src/qt/test/rpcnestedtests.cpp

build-aux/m4/bitcoin_qt.m4

@@ -116,24 +116,6 @@ AC_DEFUN([BITCOIN_QT_CONFIGURE],[
   if test "x$bitcoin_cv_static_qt" = xyes; then
     _BITCOIN_QT_FIND_STATIC_PLUGINS
     AC_DEFINE(QT_STATICPLUGIN, 1, [Define this symbol if qt plugins are static])
-    AC_CACHE_CHECK(for Qt < 5.4, bitcoin_cv_need_acc_widget,[
-      AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
-          #include <QtCore/qconfig.h>
-          #ifndef QT_VERSION
-          #  include <QtCore/qglobal.h>
-          #endif
-        ]],
-        [[
-          #if QT_VERSION >= 0x050400
-          choke
-          #endif
-        ]])],
-      [bitcoin_cv_need_acc_widget=yes],
-      [bitcoin_cv_need_acc_widget=no])
-    ])
-    if test "x$bitcoin_cv_need_acc_widget" = xyes; then
-      _BITCOIN_QT_CHECK_STATIC_PLUGINS([Q_IMPORT_PLUGIN(AccessibleFactory)], [-lqtaccessiblewidgets])
-    fi
     _BITCOIN_QT_CHECK_STATIC_PLUGINS([Q_IMPORT_PLUGIN(QMinimalIntegrationPlugin)],[-lqminimal])
     AC_DEFINE(QT_QPA_PLATFORM_MINIMAL, 1, [Define this symbol if the minimal qt platform exists])
     if test "x$TARGET_OS" = xwindows; then
@@ -279,7 +261,7 @@ dnl All macros below are internal and should _not_ be used from the main
 dnl configure.ac.
 dnl ----
 
-dnl Internal. Check if the included version of Qt is Qt5.
+dnl Internal. Check included version of Qt against minimum specified in doc/dependencies.md
 dnl Requires: INCLUDES must be populated as necessary.
 dnl Output: bitcoin_cv_qt5=yes|no
 AC_DEFUN([_BITCOIN_QT_CHECK_QT5],[
@@ -291,7 +273,7 @@ AC_DEFUN([_BITCOIN_QT_CHECK_QT5],[
       #endif
     ]],
     [[
-      #if QT_VERSION < 0x050000
+      #if QT_VERSION < 0x050501
       choke
       #endif
     ]])],

src/qt/dash.cpp

@@ -59,9 +59,6 @@
 
 #if defined(QT_STATICPLUGIN)
 #include <QtPlugin>
-#if QT_VERSION < 0x050400
-Q_IMPORT_PLUGIN(AccessibleFactory)
-#endif
 #if defined(QT_QPA_PLATFORM_XCB)
 Q_IMPORT_PLUGIN(QXcbIntegrationPlugin);
 #elif defined(QT_QPA_PLATFORM_WINDOWS)

src/qt/test/rpcnestedtests.cpp

@@ -121,7 +121,6 @@ void RPCNestedTests::rpcNestedTests()
     RPCConsole::RPCExecuteCommandLine(result, "rpcNestedTest(   abc   ,   cba )");
     QVERIFY(result == "[\"abc\",\"cba\"]");
 
-#if QT_VERSION >= 0x050300
     // do the QVERIFY_EXCEPTION_THROWN checks only with Qt5.3 and higher (QVERIFY_EXCEPTION_THROWN was introduced in Qt5.3)
     QVERIFY_EXCEPTION_THROWN(RPCConsole::RPCExecuteCommandLine(result, "getblockchaininfo() .\n"), std::runtime_error); //invalid syntax
     QVERIFY_EXCEPTION_THROWN(RPCConsole::RPCExecuteCommandLine(result, "getblockchaininfo() getblockchaininfo()"), std::runtime_error); //invalid syntax
@@ -132,5 +131,4 @@ void RPCNestedTests::rpcNestedTests()
     QVERIFY_EXCEPTION_THROWN(RPCConsole::RPCExecuteCommandLine(result, "rpcNestedTest abc,,abc"), std::runtime_error); //don't tollerate empty arguments when using ,
     QVERIFY_EXCEPTION_THROWN(RPCConsole::RPCExecuteCommandLine(result, "rpcNestedTest(abc,,abc)"), std::runtime_error); //don't tollerate empty arguments when using ,
     QVERIFY_EXCEPTION_THROWN(RPCConsole::RPCExecuteCommandLine(result, "rpcNestedTest(abc,,)"), std::runtime_error); //don't tollerate empty arguments when using ,
-#endif
 }