Bug 361975

Trying to compute "2^12" in krunner, I get a crash with this gdb backtrace:

#0  0x00007ffff45e0ea8 in __memcpy_sse2_unaligned () at /lib64/libc.so.6
#1  0x00007fffc6e411a3 in Baloo::PostingCodec::decode(QByteArray const&) () at /lib64/libKF5BalooEngine.so.5
#2  0x00007fffc6e2cebe in DBPostingIterator::DBPostingIterator(void*, unsigned int) () at /lib64/libKF5BalooEngine.so.5
#3  0x00007fffc6e2cf61 in Baloo::PostingDB::iter(QByteArray const&) () at /lib64/libKF5BalooEngine.so.5
#4  0x00007fffc6e36e5a in Baloo::Transaction::postingIterator(Baloo::EngineQuery const&) const () at /lib64/libKF5BalooEngine.so.5
#5  0x00007fffc7282a5f in Baloo::SearchStore::constructQuery(Baloo::Transaction*, Baloo::Term const&) () at /lib64/libKF5Baloo.so.5
#6  0x00007fffc7282cda in Baloo::SearchStore::constructQuery(Baloo::Transaction*, Baloo::Term const&) () at /lib64/libKF5Baloo.so.5
#7  0x00007fffc7283be9 in Baloo::SearchStore::exec(Baloo::Term const&, unsigned int, int, bool) () at /lib64/libKF5Baloo.so.5
#8  0x00007fffc72731df in Baloo::Query::exec() () at /lib64/libKF5Baloo.so.5
#9  0x00007fffc7493600 in SearchRunner::match(Plasma::RunnerContext&, QString const&, QString const&) () at /usr/lib64/qt5/plugins/krunner_baloosearchrunner.so
#10 0x00007fffc7494316 in SearchRunner::match(Plasma::RunnerContext&) () at /usr/lib64/qt5/plugins/krunner_baloosearchrunner.so
#11 0x00007fffd8ba71f8 in Plasma::AbstractRunner::performMatch(Plasma::RunnerContext&) () at /lib64/libKF5Runner.so.5
#12 0x00007fffd8986807 in ThreadWeaver::Executor::run(QSharedPointer<ThreadWeaver::JobInterface> const&, ThreadWeaver::Thread*) () at /lib64/libKF5ThreadWeaver.so.5
#13 0x00007fffd8985570 in ThreadWeaver::Job::execute(QSharedPointer<ThreadWeaver::JobInterface> const&, ThreadWeaver::Thread*) () at /lib64/libKF5ThreadWeaver.so.5
#14 0x00007fffd8984d30 in ThreadWeaver::Thread::run() () at /lib64/libKF5ThreadWeaver.so.5
#15 0x00007ffff4d26579 in QThreadPrivate::start(void*) () at /lib64/libQt5Core.so.5
#16 0x00007ffff288a65d in start_thread () at /lib64/libpthread.so.0
#17 0x00007ffff4640dad in clone () at /lib64/libc.so.6

Reproducible: Always

Steps to Reproduce:
1. Start krunner (Alt+F2)
2. Type "2^1" (without the quotes): it works OK, returns 1 and shows matching files, etc.
3. Add a 2, i.e. type "2^12": krunner crashes (sometimes before showing the result, sometimes after)
4. To get the backtrace, kill krunner and run it through gdb, then do the above steps.