fix comparison of unsigned expression < 0 (Issue #165)

IlmBase/Imath/ImathInt64.h

@@ -50,10 +50,13 @@ IMATH_INTERNAL_NAMESPACE_HEADER_ENTER
 
 #if (defined _WIN32 || defined _WIN64) && _MSC_VER >= 1300
     typedef unsigned __int64 Int64;
+    typedef __int64 SInt64;
 #elif ULONG_MAX == 18446744073709551615LU
     typedef long unsigned int Int64;
+    typedef long int SInt64;
 #else
     typedef long long unsigned int Int64;
+    typedef long long int SInt64;
 #endif
 
 

OpenEXR/IlmImf/ImfDwaCompressor.cpp

@@ -2397,15 +2397,15 @@ DwaCompressor::uncompress
                             "(truncated file).");
     }
 
-    if (unknownUncompressedSize < 0  || 
-        unknownCompressedSize < 0    ||
-        acCompressedSize < 0         || 
-        dcCompressedSize < 0         ||
-        rleCompressedSize < 0        || 
-        rleUncompressedSize < 0      ||
-        rleRawSize < 0               ||  
-        totalAcUncompressedCount < 0 || 
-        totalDcUncompressedCount < 0) 
+    if ((SInt64)unknownUncompressedSize < 0  ||
+        (SInt64)unknownCompressedSize < 0    ||
+        (SInt64)acCompressedSize < 0         ||
+        (SInt64)dcCompressedSize < 0         ||
+        (SInt64)rleCompressedSize < 0        ||
+        (SInt64)rleUncompressedSize < 0      ||
+        (SInt64)rleRawSize < 0               ||
+        (SInt64)totalAcUncompressedCount < 0 ||
+        (SInt64)totalDcUncompressedCount < 0)
     {
         throw Iex::InputExc("Error uncompressing DWA data"
                             " (corrupt header).");
@@ -2496,7 +2496,7 @@ DwaCompressor::uncompress
     // start of the data block.
     //
 
-    if ((version < 0) || (version > 2))
+    if (version > 2)
         throw Iex::InputExc ("Invalid version of compressed data block");    
 
     setupChannelData(minX, minY, maxX, maxY);

OpenEXR/IlmImf/ImfInt64.h

@@ -47,6 +47,7 @@
 OPENEXR_IMF_INTERNAL_NAMESPACE_HEADER_ENTER
 
 using IMATH_NAMESPACE::Int64;
+using IMATH_NAMESPACE::SInt64;
 
 OPENEXR_IMF_INTERNAL_NAMESPACE_HEADER_EXIT