LZMA/FLZMA: fixed wrong value of numThreads/numTotalThreads - use system number of CPUs instead of -1 (default), if compressed from FM without dialog;

closes gh-353

Author: sebres

CPP/7zip/Compress/Lzma2Encoder.cpp

@@ -8,6 +8,7 @@
 
 #include "../Common/CWrappers.h"
 #include "../Common/StreamUtils.h"
+#include "../../Windows/System.h"
 
 #include "Lzma2Encoder.h"
 #pragma warning(disable : 4127)
@@ -55,7 +56,10 @@ HRESULT SetLzma2Prop(PROPID propID, const PROPVARIANT &prop, CLzma2EncProps &lzm
     case NCoderPropID::kNumThreads:
       if (prop.vt != VT_UI4)
         return E_INVALIDARG;
-      lzma2Props.numTotalThreads = (int)(prop.ulVal);
+      lzma2Props.numTotalThreads = (
+        ((int)(prop.ulVal) > 0) ?
+        (int)(prop.ulVal) : NWindows::NSystem::GetNumberOfProcessors()
+      );
       break;
     default:
       RINOK(NLzma::SetLzmaProp(propID, prop, lzma2Props.lzmaProps))

CPP/7zip/Compress/LzmaEncoder.cpp

@@ -6,6 +6,7 @@
 
 #include "../Common/CWrappers.h"
 #include "../Common/StreamUtils.h"
+#include "../../Windows/System.h"
 
 #include "LzmaEncoder.h"
 
@@ -158,7 +159,8 @@ HRESULT SetLzmaProp(PROPID propID, const PROPVARIANT &prop, CLzmaEncProps &ep)
     SET_PROP_32(kPosStateBits, pb)
     SET_PROP_32(kLitPosBits, lp)
     SET_PROP_32(kLitContextBits, lc)
-    SET_PROP_32(kNumThreads, numThreads)
+    case NCoderPropID::kNumThreads:
+      ep.numThreads = (int)v > 0 ? (int)v : NWindows::NSystem::GetNumberOfProcessors(); break;
     default: return E_INVALIDARG;
   }
   return S_OK;