pre beta test subsurface-mobile 655

[Dirk Hohndel]

On Fri, Jan 15, 2016 at 12:22:30PM +0200, Miika Turkia wrote:
> 
> Well, it seems that the libs on the debug apk are stripped, so I fail
> to get more exact information out of this (first time trying to dig
> into tombstone, so that might affect the results as well). Anyway,
> hopefully the following back trace will give others some more info on
> the crash. At least the functions in question can be seen.
> ---8<---
> ********** Crash dump: **********
> Build fingerprint:
> 'Wileyfox/Swift/crackling:5.1.1/LMY49F/877353b5ea:userdebug/test-keys'
> pid: 6293, tid: 6319, name: QtThread  >>> org.subsurfacedivelog.mobile <<<
> signal 11 (SIGSEGV), code 1 (SEGV_MAPERR), fault addr 0xf035f188
> Stack frame #00 pc 0000fadc  /system/lib/libc.so (memcpy+96)
> Stack frame #01 pc 000e730f
> /data/app/org.subsurfacedivelog.mobile-2/lib/arm/libsubsurface-mobile.so
> (DivePlotDataModel::data(QModelIndex const&, int) const+54)
> Stack frame #02 pc 000d6275
> /data/app/org.subsurfacedivelog.mobile-2/lib/arm/libsubsurface-mobile.so
> (DiveProfileItem::paint(QPainter*, QStyleOptionGraphicsItem const*,
> QWidget*)+336)
> Stack frame #03 pc 00235d53

Yes, I was able to reproduce this (with some effort) on a desktop system,
but only if NOT running under a debugger. Nice. What is happening is that
in diveplotdatamodel.cpp we do this

QVariant DivePlotDataModel::data(const QModelIndex &index, int role) const
{
	if ((!index.isValid()) || (index.row() >= pInfo.nr))
		return QVariant();

	plot_data item = pInfo.entry[index.row()];

And that copy operation above causes memcpy to crash. 

What I haven't quite figured out, yet, is why...

/D