Bug1501: Fix bad_alloc crash for some effects with extreme inputs

src/effects/Echo.cpp

@@ -87,7 +87,16 @@ bool EffectEcho::ProcessInitialize(sampleCount WXUNUSED(totalLen), ChannelNames
 
    histPos = 0;
    histLen = (sampleCount) (mSampleRate * delay);
+
+   // Guard against extreme delay values input by the user
+   try {
       history = new float[histLen];
+   }
+   catch ( const std::bad_alloc& ) {
+      wxMessageBox(_("Requested value exceeds memory capacity."));
+      return false;
+   }
+
    memset(history, 0, sizeof(float) * histLen);
    
    return history != NULL;

src/effects/Paulstretch.cpp

@@ -223,26 +223,47 @@ void EffectPaulstretch::OnText(wxCommandEvent & WXUNUSED(evt))
    EnableApply(mUIParent->TransferDataFromWindow());
 }
 
-int EffectPaulstretch::GetBufferSize(double rate)
+size_t EffectPaulstretch::GetBufferSize(double rate)
 {
    // Audacity's fft requires a power of 2
    float tmp = rate * mTime_resolution / 2.0;
    tmp = log(tmp) / log(2.0);
    tmp = pow(2.0, floor(tmp + 0.5));
 
-   return std::max<int>((int)tmp, 128);
+   auto stmp = size_t(tmp);
+   if (stmp != tmp)
+      // overflow
+      return 0;
+   if (stmp >= 2 * stmp)
+      // overflow
+      return 0;
+
+   return std::max<size_t>(stmp, 128);
 }
 
 bool EffectPaulstretch::ProcessOne(WaveTrack *track,double t0,double t1,int count)
 {
-   int stretch_buf_size = GetBufferSize(track->GetRate());
+   auto badAllocMessage = _("Requested value exceeds memory capacity.");
+
+   const auto stretch_buf_size = GetBufferSize(track->GetRate());
+   if (stretch_buf_size == 0) {
+      ::wxMessageBox( badAllocMessage );
+      return false;
+   }
+
    double amount = this->mAmount;
 
    auto start = track->TimeToLongSamples(t0);
    auto end = track->TimeToLongSamples(t1);
    auto len = end - start;
 
-   int minDuration = stretch_buf_size * 2 + 1;
+   const auto minDuration = stretch_buf_size * 2 + 1;
+   if (minDuration < stretch_buf_size) {
+      // overflow!
+      ::wxMessageBox( badAllocMessage );
+      return false;
+   }
+
    if (len < minDuration){   //error because the selection is too short
 
       float maxTimeRes = log(len) / log(2.0);
@@ -290,6 +311,10 @@ bool EffectPaulstretch::ProcessOne(WaveTrack *track,double t0,double t1,int coun
 
    auto outputTrack = mFactory->NewWaveTrack(track->GetSampleFormat(),track->GetRate());
 
+   try {
+      // This encloses all the allocations of buffers, including those in
+      // the constructor of the PaulStretch object
+
       PaulStretch stretch(amount,stretch_buf_size,track->GetRate());
 
       auto nget = stretch.get_nsamples_for_fill();
@@ -353,6 +378,11 @@ bool EffectPaulstretch::ProcessOne(WaveTrack *track,double t0,double t1,int coun
       delete []buffer0;
       
       return !cancelled;
+   }
+   catch ( const std::bad_alloc& ) {
+      ::wxMessageBox( badAllocMessage );
+      return false;
+   }
 };
 
 /*************************************************************/

src/effects/Paulstretch.h

@@ -50,7 +50,7 @@ private:
    // EffectPaulstretch implementation
    
    void OnText(wxCommandEvent & evt);
-   int GetBufferSize(double rate);
+   size_t GetBufferSize(double rate);
 
    bool ProcessOne(WaveTrack *track, double t0, double t1, int count);