mesa: in glReadBufer() set _NEW_BUFFERS, not _NEW_PIXEL

Since GL_READ_BUFFER is historically part of the gl_pixel_attrib group
it made sense to signal changes with _NEW_PIXEL.  But now with FBOs it's
also part of the framebuffer state.

Now _NEW_PIXEL strictly indicates pixels transfer state changes.

This change avoids framebuffer state validation when any random bit of
pixel-transfer state is set.

DRI drivers updated too:  don't check _NEW_COLOR when updating framebuffer
state.  I think that was just copied from the Xlib driver because we care
about dither enable/disable state there.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/mesa/main/buffers.c b/src/mesa/main/buffers.c
index c5f13345f04..d8b5f3b1f4a 100644
--- a/src/mesa/main/buffers.c
+++ b/src/mesa/main/buffers.c
@@ -443,7 +443,7 @@ _mesa_readbuffer(GLcontext *ctx, GLenum buffer, GLint bufferIndex)
    fb->ColorReadBuffer = buffer;
    fb->_ColorReadBufferIndex = bufferIndex;
 
-   ctx->NewState |= _NEW_PIXEL;
+   ctx->NewState |= _NEW_BUFFERS;
 }