From 10ab9c2f4279e182f61a86a65f3a9b9cdba1df83 Mon Sep 17 00:00:00 2001
From: Jeff Garzik <jeff@garzik.org>
Date: Tue, 1 May 2012 17:50:33 -0400
Subject: [PATCH] OpenBlockFile(): cast to eliminate signed/unsigned comparison
 warning

nFile's null value is -1.  Cast that to unsigned int, to avoid warning.

Additionally, avoid nFile==0 because the first valid value is 1.
---
 src/main.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/main.cpp b/src/main.cpp
index 427e435a9..78427e0d3 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -1836,7 +1836,7 @@ bool CheckDiskSpace(uint64 nAdditionalBytes)
 
 FILE* OpenBlockFile(unsigned int nFile, unsigned int nBlockPos, const char* pszMode)
 {
-    if (nFile == -1)
+    if ((nFile < 1) || (nFile == (unsigned int) -1))
         return NULL;
     FILE* file = fopen((GetDataDir() / strprintf("blk%04d.dat", nFile)).string().c_str(), pszMode);
     if (!file)