Fix RED-603: Errors when loading local images

Avoid bad offsets that would cause failure with this warning:
"doRead: Error reading file from local cache"

1 files changed, 3 insertions, 2 deletions

diff --git a/linden/indra/newview/lltexturecache.cpp b/linden/indra/newview/lltexturecache.cpp
index 46c125f..0c35b32 100644
--- a/linden/indra/newview/lltexturecache.cpp
+++ b/linden/indra/newview/lltexturecache.cpp
@@ -372,9 +372,10 @@ bool LLTextureCacheRemoteWorker::doRead()
         if (!done && (mState == LOCAL))
         {
                 llassert(local_size != 0);      // we're assuming there is a non empty local file here...
-                if (!mDataSize || mDataSize > local_size)
+                llassert(mReadData == NULL);
+                if (!mDataSize || mDataSize > (local_size - mOffset))
                 {
-                        mDataSize = local_size;
+                        mDataSize = local_size - mOffset;
                 }
                 // Allocate read buffer
                 mReadData = new U8[mDataSize];