From 1e16c002795db2e8b30b9750df22683bd50fac16 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Stephan=20A=C3=9Fmus?= <superstippi@gmx.de>
Date: Wed, 24 Mar 2010 16:48:33 +0000
Subject: [PATCH]  * Don't store a possibly negative return value in an
 unsigned size_t, which    is later used as parameter to memcpy(). Should fix
 r5623 (untested).  * Fixed coding style for some comments.

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35944 a95241bf-73f2-0310-859d-f6bbb57e9c96
---
 src/kits/support/BufferIO.cpp | 20 ++++++++++++++------
 1 file changed, 14 insertions(+), 6 deletions(-)

diff --git a/src/kits/support/BufferIO.cpp b/src/kits/support/BufferIO.cpp
index a3aa536a0c..f6d1cc9afd 100644
--- a/src/kits/support/BufferIO.cpp
+++ b/src/kits/support/BufferIO.cpp
@@ -73,14 +73,21 @@ BBufferIO::ReadAt(off_t pos, void* buffer, size_t size)
 		|| pos < fBufferStart
 		|| pos > fBufferStart + fBufferUsed
 		|| pos + size > fBufferStart + fBufferUsed) {
-		if (fBufferIsDirty)
-			Flush(); // If there are pending writes, do them.
+		if (fBufferIsDirty) {
+			// If there are pending writes, do them.
+			Flush();
+		}
 
 		// ...cache as much as we can from the stream
-		fBufferUsed = fStream->ReadAt(pos, fBuffer, fBufferSize);
+		ssize_t sizeRead = fStream->ReadAt(pos, fBuffer, fBufferSize);
+		if (sizeRead < 0)
+			return sizeRead;
 
-		if (fBufferUsed > 0)
-			fBufferStart = pos; // The data is buffered starting from this offset
+		fBufferUsed = sizeRead;
+		if (fBufferUsed > 0) {
+			// The data is buffered starting from this offset
+			fBufferStart = pos;
+		}
 	}
 
 	size = min_c(size, fBufferUsed);
@@ -117,7 +124,8 @@ BBufferIO::WriteAt(off_t pos, const void* buffer, size_t size)
 		ssize_t read;
 		off_t where = pos;
 
-		if (pos + size <= fBufferSize) // Can we just cache from the beginning ?
+		// Can we just cache from the beginning?
+		if (pos + size <= fBufferSize)
 			where = 0;
 
 		// ...cache more.