Bug#929682: libqt5qml5: QQmlEngine segfaults on ia64

[Jason Duerstock <jason.duerstock@gmail.com>]

Source: qtdeclarative-opensource-src
Severity: important
Tags: patch
User: debian-ia64@lists.debian.org
Usertags: ia64

Dear Maintainer,

As reported in bug #894726, qtdeclarative-opensource-src has a bug on
systems that use 64-bit pointers with any bits from 63-50 set.  The
attached patch addresses this issue on ia64 by shifting bits 63-61
(which are the "virtual region number" on ia64) into bits 49-47.  Please
include it in the next release.

Thank you.

-- System Information:
Debian Release: 10.0
  APT prefers unreleased
  APT policy: (500, 'unreleased'), (500, 'unstable')
Architecture: ia64

Kernel: Linux 5.0.0-trunk-mckinley (SMP w/2 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

--- a/src/qml/jsruntime/qv4value_p.h	2019-05-24 21:55:24.436238822 -0400
+++ b/src/qml/jsruntime/qv4value_p.h	2019-05-24 22:08:26.832635233 -0400
@@ -146,12 +146,24 @@
     QML_NEARLY_ALWAYS_INLINE Heap::Base *m() const
     {
         Heap::Base *b;
-        memcpy(&b, &_val, 8);
+#ifdef __ia64
+	quint64 _tmp;
+
+	_tmp = _val & 0x0001c00000000000;
+	_tmp = (_tmp << 14) | (_val ^ _tmp);
+	memcpy(&b, &_tmp, 8);
+#else
+	memcpy(&b, &_val, 8);
+#endif
         return b;
     }
     QML_NEARLY_ALWAYS_INLINE void setM(Heap::Base *b)
     {
         memcpy(&_val, &b, 8);
+#ifdef __ia64
+	_val |= ((_val & 0xa000000000000000) >> 14);
+	_val &= 0x0001ffffffffffff;
+#endif
     }
 #elif QT_POINTER_SIZE == 4
     QML_NEARLY_ALWAYS_INLINE Heap::Base *m() const