unchanged:
--- a/src/mesa/drivers/dri/radeon/radeon_context.c
+++ b/src/mesa/drivers/dri/radeon/radeon_context.c
@@ -594,12 +594,14 @@ radeonMakeCurrent( __DRIcontextPrivate *
 	 driDrawableInitVBlank( driDrawPriv, newCtx->vblank_flags,
 				&newCtx->vbl_seq );
       }
-      
-      if ( (newCtx->dri.drawable != driDrawPriv)
-	   || (newCtx->dri.readable != driReadPriv) ) {
+
+      newCtx->dri.readable = driReadPriv;
+
+      if ( (newCtx->dri.drawable != driDrawPriv) ||
+           newCtx->lastStamp != driDrawPriv->lastStamp ) {
 	 newCtx->dri.drawable = driDrawPriv;
-	 newCtx->dri.readable = driReadPriv;
 
+	 radeonSetCliprects(newCtx);
 	 radeonUpdateWindow( newCtx->glCtx );
 	 radeonUpdateViewportOffset( newCtx->glCtx );
       }
unchanged:
--- a/src/mesa/drivers/dri/radeon/radeon_lock.c
+++ b/src/mesa/drivers/dri/radeon/radeon_lock.c
@@ -96,7 +96,6 @@ void radeonGetLock( radeonContextPtr rme
       radeonSetCliprects( rmesa );
       radeonUpdateViewportOffset( rmesa->glCtx );
       driUpdateFramebufferSize(rmesa->glCtx, drawable);
-      rmesa->lastStamp = drawable->lastStamp;
    }
 
    RADEON_STATECHANGE( rmesa, ctx );
unchanged:
--- a/src/mesa/drivers/dri/radeon/radeon_state.c
+++ b/src/mesa/drivers/dri/radeon/radeon_state.c
@@ -1675,6 +1675,8 @@ void radeonSetCliprects( radeonContextPt
 
    if (rmesa->state.scissor.enabled)
       radeonRecalcScissorRects( rmesa );
+
+   rmesa->lastStamp = drawable->lastStamp;
 }
 
 
unchanged:
--- b/src/mesa/drivers/dri/r200/r200_context.c
+++ b/src/mesa/drivers/dri/r200/r200_context.c
@@ -673,11 +673,13 @@
 				&newCtx->vbl_seq );
       }
 
+      newCtx->dri.readable = driReadPriv;
+
       if ( newCtx->dri.drawable != driDrawPriv ||
-           newCtx->dri.readable != driReadPriv ) {
+           newCtx->lastStamp != driDrawPriv->lastStamp ) {
 	 newCtx->dri.drawable = driDrawPriv;
-	 newCtx->dri.readable = driReadPriv;
 
+	 r200SetCliprects(newCtx);
 	 r200UpdateWindow( newCtx->glCtx );
 	 r200UpdateViewportOffset( newCtx->glCtx );
       }
unchanged:
--- b/src/mesa/drivers/dri/r200/r200_lock.c
+++ b/src/mesa/drivers/dri/r200/r200_lock.c
@@ -92,13 +92,9 @@
 
    if ( rmesa->lastStamp != drawable->lastStamp ) {
       r200UpdatePageFlipping( rmesa );
-      if (rmesa->glCtx->DrawBuffer->_ColorDrawBufferMask[0] == BUFFER_BIT_BACK_LEFT)
-         r200SetCliprects( rmesa, GL_BACK_LEFT );
-      else
-         r200SetCliprects( rmesa, GL_FRONT_LEFT );
+      r200SetCliprects( rmesa );
       r200UpdateViewportOffset( rmesa->glCtx );
       driUpdateFramebufferSize(rmesa->glCtx, drawable);
-      rmesa->lastStamp = drawable->lastStamp;
    }
 
    R200_STATECHANGE( rmesa, ctx );
unchanged:
--- b/src/mesa/drivers/dri/r200/r200_state.c
+++ b/src/mesa/drivers/dri/r200/r200_state.c
@@ -1691,6 +1691,11 @@
 #define SUBPIXEL_X 0.125
 #define SUBPIXEL_Y 0.125
 
+
+/**
+ * Called when window size or position changes or viewport or depth range
+ * state is changed.  We update the hardware viewport state here.
+ */
 void r200UpdateWindow( GLcontext *ctx )
 {
    r200ContextPtr rmesa = R200_CONTEXT(ctx);
@@ -1843,19 +1848,18 @@
 }
 
 
-void r200SetCliprects( r200ContextPtr rmesa, GLenum mode )
+/*
+ * Set up the cliprects for either front or back-buffer drawing.
+ */
+void r200SetCliprects( r200ContextPtr rmesa )
 {
    __DRIdrawablePrivate *const drawable = rmesa->dri.drawable;
    __DRIdrawablePrivate *const readable = rmesa->dri.readable;
    GLframebuffer *const draw_fb = (GLframebuffer*) drawable->driverPrivate;
    GLframebuffer *const read_fb = (GLframebuffer*) readable->driverPrivate;
 
-   switch ( mode ) {
-   case GL_FRONT_LEFT:
-      rmesa->numClipRects = drawable->numClipRects;
-      rmesa->pClipRects = drawable->pClipRects;
-      break;
-   case GL_BACK_LEFT:
+   if (draw_fb->_ColorDrawBufferMask[0]
+       == BUFFER_BIT_BACK_LEFT) {
       /* Can't ignore 2d windows if we are page flipping.
        */
       if ( drawable->numBackClipRects == 0 || rmesa->doPageFlip ) {
@@ -1866,11 +1870,12 @@
          rmesa->numClipRects = drawable->numBackClipRects;
          rmesa->pClipRects = drawable->pBackClipRects;
       }
-      break;
-   default:
-      fprintf(stderr, "bad mode in r200SetCliprects\n");
-      return;
    }
+   else {
+     /* front buffer (or none, or multiple buffers) */
+     rmesa->numClipRects = drawable->numClipRects;
+     rmesa->pClipRects = drawable->pClipRects;
+  }
 
    if ((draw_fb->Width != drawable->w) || (draw_fb->Height != drawable->h)) {
       _mesa_resize_framebuffer(rmesa->glCtx, draw_fb,
@@ -1889,6 +1894,8 @@
 
    if (rmesa->state.scissor.enabled)
       r200RecalcScissorRects( rmesa );
+
+   rmesa->lastStamp = drawable->lastStamp;
 }
 
 
@@ -1908,19 +1915,17 @@
     */
    switch ( ctx->DrawBuffer->_ColorDrawBufferMask[0] ) {
    case BUFFER_BIT_FRONT_LEFT:
-      FALLBACK( rmesa, R200_FALLBACK_DRAW_BUFFER, GL_FALSE );
-      r200SetCliprects( rmesa, GL_FRONT_LEFT );
-      break;
    case BUFFER_BIT_BACK_LEFT:
       FALLBACK( rmesa, R200_FALLBACK_DRAW_BUFFER, GL_FALSE );
-      r200SetCliprects( rmesa, GL_BACK_LEFT );
       break;
    default:
-      /* GL_NONE or GL_FRONT_AND_BACK or stereo left&right, etc */
+      /* 0 (GL_NONE) buffers or multiple color drawing buffers */
       FALLBACK( rmesa, R200_FALLBACK_DRAW_BUFFER, GL_TRUE );
       return;
    }
 
+   r200SetCliprects( rmesa );
+
    /* We'll set the drawing engine's offset/pitch parameters later
     * when we update other state.
     */
unchanged:
--- a/src/mesa/drivers/dri/r200/r200_state.h
+++ b/src/mesa/drivers/dri/r200/r200_state.h
@@ -44,7 +44,7 @@ extern void r200InitTnlFuncs( GLcontext
 
 extern void r200UpdateMaterial( GLcontext *ctx );
 
-extern void r200SetCliprects( r200ContextPtr rmesa, GLenum mode );
+extern void r200SetCliprects( r200ContextPtr rmesa );
 extern void r200RecalcScissorRects( r200ContextPtr rmesa );
 extern void r200UpdateViewportOffset( GLcontext *ctx );
 extern void r200UpdateWindow( GLcontext *ctx );
only in patch2:
unchanged:
--- b/src/mesa/drivers/dri/r300/radeon_context.c
+++ b/src/mesa/drivers/dri/r300/radeon_context.c
@@ -51,6 +51,7 @@
 #include "radeon_macros.h"
 #include "radeon_reg.h"
 
+#include "radeon_state.h"
 #include "r300_state.h"
 
 #include "utils.h"
@@ -272,11 +273,13 @@
 					      &radeon->vbl_seq);
 		}
 
+		radeon->dri.readable = driReadPriv;
+
 		if (radeon->dri.drawable != driDrawPriv ||
-		    radeon->dri.readable != driReadPriv) {
+		    radeon->lastStamp != driDrawPriv->lastStamp) {
 			radeon->dri.drawable = driDrawPriv;
-			radeon->dri.readable = driReadPriv;
 
+			radeonSetCliprects(radeon);
 			r300UpdateWindow(radeon->glCtx);
 			r300UpdateViewportOffset(radeon->glCtx);
 		}
only in patch2:
unchanged:
--- a/src/mesa/drivers/dri/r300/radeon_lock.c
+++ b/src/mesa/drivers/dri/r300/radeon_lock.c
@@ -90,7 +90,6 @@ static void r300RegainedLock(radeonConte
 #else
 		radeonUpdateScissor(radeon->glCtx);
 #endif
-		radeon->lastStamp = drawable->lastStamp;
 	}
 
 	if (sarea->ctx_owner != radeon->dri.hwContext) {
only in patch2:
unchanged:
--- a/src/mesa/drivers/dri/r300/radeon_state.c
+++ b/src/mesa/drivers/dri/r300/radeon_state.c
@@ -185,6 +185,8 @@ void radeonSetCliprects(radeonContextPtr
 
 	if (radeon->state.scissor.enabled)
 		radeonRecalcScissorRects(radeon);
+
+	radeon->lastStamp = drawable->lastStamp;
 }