[Scummvm-cvs-logs] scummvm master -> 5bfd2f675620f69e23cefbaf8553cb341a9f992c

[lordhoto]

This automated email contains information about 1 new commit which have been
pushed to the 'scummvm' repo located at https://github.com/scummvm/scummvm .

Summary:
5bfd2f6756 COMMON: Fix successive seeks in BufferedSeekableReadStream.


Commit: 5bfd2f675620f69e23cefbaf8553cb341a9f992c
    https://github.com/scummvm/scummvm/commit/5bfd2f675620f69e23cefbaf8553cb341a9f992c
Author: Johannes Schickel (lordhoto at scummvm.org)
Date: 2013-01-28T08:34:37-08:00

Commit Message:
COMMON: Fix successive seeks in BufferedSeekableReadStream.

This fixes the failing test case added in
da8eeb9dbed2102764b3ca0697d6882bae0402cc.

Thanks to wjp for his input on this.

Changed paths:
    common/stream.cpp



diff --git a/common/stream.cpp b/common/stream.cpp
index 57b1b8b..2851b3a 100644
--- a/common/stream.cpp
+++ b/common/stream.cpp
@@ -393,7 +393,14 @@ bool BufferedSeekableReadStream::seek(int32 offset, int whence) {
 		// just seek normally in the parent stream.
 		if (whence == SEEK_CUR)
 			offset -= (_bufSize - _pos);
-		_pos = _bufSize;
+		// We invalidate the buffer here. This assures that successive seeks
+		// do not have the chance to incorrectly think they seeked back into
+		// the buffer.
+		// Note: This does not take full advantage of the buffer. But it is
+		// a simple way to prevent nasty errors. It would be possible to take
+		// full advantage of the buffer by saving its actual start position.
+		// This seems not worth the effort for this seemingly uncommon use.
+		_pos = _bufSize = 0;
 		_parentStream->seek(offset, whence);
 	}