division by zero

[LubuntuSharp]

Describe the bug A division by zero comes out

To Reproduce GDB SHOWS OpenHantek6022-3.0.3/openhantek/src/hantekdso/hantekdsocontrol.cpp LINE 549 result.data[channel].resize( sampleCount / rawDownsampling ); rawDownsampling can happen to be equal to zero at run-time (I solved by defaulting resize argument to 1 instead of getting division by zero)

System info:

• OpenHantek version: OpenHantek6022-303
• OS: Lubuntu 16.04
• Distribution, version: x86 32 bit
• Video hardware: [Intel Integrated Graphics]
• C++ compiler version: gcc (Ubuntu 5.4.0-6ubuntu1~16.04.12) 5.4.0 20160609

Scope device (please complete the following information):

• Device Hantek 6022BE, ...]
• Program top line [e.g. OpenHantek6022 (Build ...) - Device ... (FW 0205)]

Additional context I run with --useGLES option

[Ho-Ro]

ok, from data flow it shouldn't happen:

unsigned HantekDsoControl::getRecordLength() const {
    unsigned rawsize = SAMPLESIZE_USED; // = 20000
    rawsize *= this->downsamplingNumber; // take more samples
    rawsize = ( (rawsize + 1024) / 1024 + 2 ) * 1024; // adjust for skipping of minimal 2018 leading samples
    //printf( "getRecordLength: %d\n", rawsize );
    return rawsize;
}

...

const unsigned rawSampleCount = unsigned( isFastRate() ? rawData.size() : (rawData.size() / 2) );
//printf("cRDTS, rawSampleCount %lu\n", rawSampleCount);
if ( 0 == rawSampleCount) // nothing to convert
    return;
...
unsigned sampleCount = (rawSampleCount > 1024) ? ((rawSampleCount - 1024)/1000 - 1)*1000 : rawSampleCount;
...
unsigned rawDownsampling = sampleCount / SAMPLESIZE_USED;
....
result.data[channel].resize( sampleCount / rawDownsampling );

but I've included more safeguarding with a933b52