net/qt5-network: Add patch from Qt upstream fixing QDnsLookup.

This should fix bug in net-im/psi, when connecting to some servers was failing.

Reviewed by:	tcberner (mentor)

net/qt5-network/Makefile

@@ -2,6 +2,7 @@
 
 PORTNAME=	network
 DISTVERSION=	${QT5_VERSION}
+PORTREVISION=	1
 CATEGORIES=	net ipv6
 PKGNAMEPREFIX=	qt5-
 

net/qt5-network/files/patch-qdnslookup

@@ -0,0 +1,109 @@
+QDnsLookup: fix "Resolver functions not found" error on FreeBSD
+
+The current code only tries to load the required functions from
+LIBRESOLV_SO (if defined) and resolv, but on FreeBSD they are in libc:
+https://www.freebsd.org/cgi/man.cgi?query=res_query&sektion=3&apropos=0&manpath=freebsd
+
+This commit changes the code so that, after failing to load the
+non-existent libraries, it attempts to load the functions with dlsym()
+using the special handle RTLD_DEFAULT, which searches for the specified
+symbol in the loaded libraries.
+
+Task-number: QTBUG-74844
+
+diff --git a/src/network/kernel/kernel.pri b/src/network/kernel/kernel.pri
+index 11b80d59d5e..d7a92a12ebe 100644
+--- src/network/kernel/kernel.pri
++++ src/network/kernel/kernel.pri
+@@ -38,7 +38,11 @@ qtConfig(dnslookup) {
+ }
+ 
+ unix {
+-    !integrity:qtConfig(dnslookup): SOURCES += kernel/qdnslookup_unix.cpp
++    !integrity:qtConfig(dnslookup) {
++        SOURCES += kernel/qdnslookup_unix.cpp
++        qtConfig(dlopen): QMAKE_USE_PRIVATE += libdl
++    }
++
+     SOURCES += kernel/qhostinfo_unix.cpp
+ 
+     qtConfig(linux-netlink): SOURCES += kernel/qnetworkinterface_linux.cpp
+diff --git a/src/network/kernel/qdnslookup_unix.cpp b/src/network/kernel/qdnslookup_unix.cpp
+index ce1ec6442a6..ee7484ab35f 100644
+--- src/network/kernel/qdnslookup_unix.cpp
++++ src/network/kernel/qdnslookup_unix.cpp
+@@ -59,6 +59,10 @@
+ #  include <gnu/lib-names.h>
+ #endif
+ 
++#if defined(Q_OS_FREEBSD) || QT_CONFIG(dlopen)
++#  include <dlfcn.h>
++#endif
++
+ #include <cstring>
+ 
+ QT_BEGIN_NAMESPACE
+@@ -87,6 +91,18 @@ struct QDnsLookupStateDeleter
+     }
+ };
+ 
++static QFunctionPointer resolveSymbol(QLibrary &lib, const char *sym)
++{
++    if (lib.isLoaded())
++        return lib.resolve(sym);
++
++#if defined(RTLD_DEFAULT) && (defined(Q_OS_FREEBSD) || QT_CONFIG(dlopen))
++    return reinterpret_cast<QFunctionPointer>(dlsym(RTLD_DEFAULT, sym));
++#else
++    return nullptr;
++#endif
++}
++
+ static bool resolveLibraryInternal()
+ {
+     QLibrary lib;
+@@ -96,31 +112,30 @@ static bool resolveLibraryInternal()
+ #endif
+     {
+         lib.setFileName(QLatin1String("resolv"));
+-        if (!lib.load())
+-            return false;
++        lib.load();
+     }
+ 
+-    local_dn_expand = dn_expand_proto(lib.resolve("__dn_expand"));
++    local_dn_expand = dn_expand_proto(resolveSymbol(lib, "__dn_expand"));
+     if (!local_dn_expand)
+-        local_dn_expand = dn_expand_proto(lib.resolve("dn_expand"));
++        local_dn_expand = dn_expand_proto(resolveSymbol(lib, "dn_expand"));
+ 
+-    local_res_nclose = res_nclose_proto(lib.resolve("__res_nclose"));
++    local_res_nclose = res_nclose_proto(resolveSymbol(lib, "__res_nclose"));
+     if (!local_res_nclose)
+-        local_res_nclose = res_nclose_proto(lib.resolve("res_9_nclose"));
++        local_res_nclose = res_nclose_proto(resolveSymbol(lib, "res_9_nclose"));
+     if (!local_res_nclose)
+-        local_res_nclose = res_nclose_proto(lib.resolve("res_nclose"));
++        local_res_nclose = res_nclose_proto(resolveSymbol(lib, "res_nclose"));
+ 
+-    local_res_ninit = res_ninit_proto(lib.resolve("__res_ninit"));
++    local_res_ninit = res_ninit_proto(resolveSymbol(lib, "__res_ninit"));
+     if (!local_res_ninit)
+-        local_res_ninit = res_ninit_proto(lib.resolve("res_9_ninit"));
++        local_res_ninit = res_ninit_proto(resolveSymbol(lib, "res_9_ninit"));
+     if (!local_res_ninit)
+-        local_res_ninit = res_ninit_proto(lib.resolve("res_ninit"));
++        local_res_ninit = res_ninit_proto(resolveSymbol(lib, "res_ninit"));
+ 
+-    local_res_nquery = res_nquery_proto(lib.resolve("__res_nquery"));
++    local_res_nquery = res_nquery_proto(resolveSymbol(lib, "__res_nquery"));
+     if (!local_res_nquery)
+-        local_res_nquery = res_nquery_proto(lib.resolve("res_9_nquery"));
++        local_res_nquery = res_nquery_proto(resolveSymbol(lib, "res_9_nquery"));
+     if (!local_res_nquery)
+-        local_res_nquery = res_nquery_proto(lib.resolve("res_nquery"));
++        local_res_nquery = res_nquery_proto(resolveSymbol(lib, "res_nquery"));
+ 
+     return true;
+ }
+