webbrowser-app test failure on armhf with Qt 5.3

[Timo Jyrinki]

With the FTBFS bug fixed, it seems there's still a test failure on armhf only when using Qt 5.3:

https://launchpadlibrarian.net/176026671/buildlog_ubuntu-utopic-armhf.webbrowser-app_1%3A0.23%2B14.10.20140515.1-0~537%2B201405201947~ubuntu14.10.1%2Bfixqt53~test1_FAILEDTOBUILD.txt.gz

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 4/12 Test #1: tst_QmlTests ...................................***Failed 1.12 sec
libEGL warning: GLX/DRI2 is not supported
file:///build/buildd/webbrowser-app-0.23+14.10.20140515.1/obj-arm-linux-gnueabihf/tests/unittests/qml/undertest/AddressBar.qml:55:13: QML QQuickImage: Cannot open: file:///build/buildd/webbrowser-app-0.23+14.10.20140515.1/obj-arm-linux-gnueabihf/tests/unittests/qml/undertest/assets/reload.png
process 18699: D-Bus library appears to be incorrectly set up; failed to read machine uuid: Failed to open "/etc/machine-id": No such file or directory
See the manual page for dbus-uuidgen to correct this issue.
********* Start testing of QmlTests *********
Config: Using QtTest library 5.3.0, Qt 5.3.0
PASS : QmlTests::AddressBar::initTestCase()
Segmentation fault
---

--
Refer to kept-update info on the front page of https://launchpad.net/~canonical-qt5-edgers/+archive/qt5-beta2 regarding where/how to get Qt 5.3. Note that it's not necessarily that PPA itself.

[Olivier Tilloy (osomon)]

The failure is actually a segfault, here is the backtrace I managed to get (running the tests on a chromebook):

********* Start testing of QmlTests *********
Config: Using QtTest library 5.3.0, Qt 5.3.0
PASS : QmlTests::AddressBar::initTestCase()

Program received signal SIGSEGV, Segmentation fault.
QV4::StringPrototype::method_split (ctx=<optimized out>) at jsruntime/qv4scopedvalue_p.h:313
313 jsruntime/qv4scopedvalue_p.h: No such file or directory.
(gdb) bt
#0 QV4::StringPrototype::method_split (ctx=<optimized out>) at jsruntime/qv4scopedvalue_p.h:313
#1 0xb613024e in QV4::BuiltinFunction::call (that=<optimized out>, callData=<optimized out>) at jsruntime/qv4functionobject.cpp:583
#2 0xb6164c68 in call (d=0xaff020e8, this=<optimized out>) at jsruntime/qv4object_p.h:270
#3 QV4::Runtime::callProperty (context=0xbeffe678, name=..., callData=...) at jsruntime/qv4runtime.cpp:938
#4 0xafacb0ba in ?? ()
Backtrace stopped: previous frame identical to this frame (corrupt stack?)

[Olivier Tilloy (osomon)]

I’m seeing a different backtrace when commenting out a few tests (thus getting some tests to pass):

Program received signal SIGSEGV, Segmentation fault.
0xb6f0baa8 in __memcpy_neon () at ../ports/sysdeps/arm/armv7/multiarch/memcpy_impl.S:332
332 ../ports/sysdeps/arm/armv7/multiarch/memcpy_impl.S: No such file or directory.
(gdb) bt
#0 0xb6f0baa8 in __memcpy_neon () at ../ports/sysdeps/arm/armv7/multiarch/memcpy_impl.S:332
#1 0xb6564892 in memcpy (__len=<optimized out>, __src=<optimized out>, __dest=<optimized out>) at /usr/include/arm-linux-gnueabihf/bits/string3.h:51
#2 QString::append (this=this@entry=0xbeffe538, str=...) at tools/qstring.cpp:8695
#3 0xb6144122 in operator+= (s=..., this=0xbeffe538) at /usr/include/arm-linux-gnueabihf/qt5/QtCore/qstring.h:411
#4 QV4::StringPrototype::method_replace (ctx=<optimized out>) at jsruntime/qv4stringobject.cpp:593
#5 0xb613024e in QV4::BuiltinFunction::call (that=<optimized out>, callData=<optimized out>) at jsruntime/qv4functionobject.cpp:583
#6 0xb6164c68 in call (d=0xaff01eb0, this=<optimized out>) at jsruntime/qv4object_p.h:270
#7 QV4::Runtime::callProperty (context=0xbeffe7c0, name=..., callData=...) at jsruntime/qv4runtime.cpp:938
#8 0xaba068dc in ?? ()
Backtrace stopped: previous frame identical to this frame (corrupt stack?)

[Olivier Tilloy (osomon)]

When running the tests with QV4_FORCE_INTERPRETER=1, the crash goes away and the tests pass.

[Timo Jyrinki (timo-jyrinki)]

As discussed, this may be similar to the upstream split string problem that was workarounded successfully in UI Toolkit:
http://bazaar.launchpad.net/~ubuntu-sdk-team/ubuntu-ui-toolkit/staging/revision/1080

Another very big fix in many apps resulted from this UI Toolkit fix adding default keyword too:
http://bazaar.launchpad.net/~ubuntu-sdk-team/ubuntu-ui-toolkit/staging/revision/1085

The armhf crasher related to the split function is tracked at bug #1323997

[Timo Jyrinki (timo-jyrinki)]

I'll mark this as Fix Committed to indicate that it has landed to landing PPA.