meta: Fix invalid PBO access from DrawPixels when trying to just alloc.

This whole reuse of buffers (TexSubImage instead of TexImage, SubData
instead of Data) is bad for hardware drivers, but it's even worse when
we accidentally try to access the 2x2 PBO to fill the new 16x16 texture
we're creating, producing GL errors.

Fixes piglit pbo-drawpixels.  Bug #14163.

1 files changed, 15 insertions, 6 deletions

diff --git a/src/mesa/drivers/common/meta.c b/src/mesa/drivers/common/meta.c
index b445323aab..a152087a3a 100644
--- a/src/mesa/drivers/common/meta.c
+++ b/src/mesa/drivers/common/meta.c
@@ -974,7 +974,8 @@ setup_copypix_texture(struct temp_texture *tex,
  * Setup/load texture for glDrawPixels.
  */
 static void
-setup_drawpix_texture(struct temp_texture *tex,
+setup_drawpix_texture(GLcontext *ctx,
+		      struct temp_texture *tex,
                       GLboolean newTex,
                       GLenum texIntFormat,
                       GLsizei width, GLsizei height,
@@ -995,9 +996,17 @@ setup_drawpix_texture(struct temp_texture *tex,
                           tex->Width, tex->Height, 0, format, type, pixels);
       }
       else {
+	 struct gl_buffer_object *save_unpack_obj = NULL;
+
+	 _mesa_reference_buffer_object(ctx, &save_unpack_obj,
+				       ctx->Unpack.BufferObj);
+	 _mesa_BindBufferARB(GL_PIXEL_UNPACK_BUFFER_ARB, 0);
          /* create empty texture */
          _mesa_TexImage2D(tex->Target, 0, tex->IntFormat,
                           tex->Width, tex->Height, 0, format, type, NULL);
+	 if (save_unpack_obj != NULL)
+	    _mesa_BindBufferARB(GL_PIXEL_UNPACK_BUFFER_ARB,
+				save_unpack_obj->Name);
          /* load image */
          _mesa_TexSubImage2D(tex->Target, 0,
                              0, 0, width, height, format, type, pixels);
@@ -1162,7 +1171,7 @@ _mesa_meta_BlitFramebuffer(GLcontext *ctx,
          _mesa_ReadPixels(srcX, srcY, srcW, srcH,
                           GL_DEPTH_COMPONENT, GL_UNSIGNED_INT, tmp);
 
-         setup_drawpix_texture(tex, newTex, GL_DEPTH_COMPONENT, srcW, srcH,
+         setup_drawpix_texture(ctx, tex, newTex, GL_DEPTH_COMPONENT, srcW, srcH,
                                GL_DEPTH_COMPONENT, GL_UNSIGNED_INT, tmp);
 
          _mesa_BindProgram(GL_FRAGMENT_PROGRAM_ARB, blit->DepthFP);
@@ -1725,7 +1734,7 @@ _mesa_meta_DrawPixels(GLcontext *ctx,
       if (!drawpix->StencilFP)
          init_draw_stencil_pixels(ctx);
 
-      setup_drawpix_texture(tex, newTex, texIntFormat, width, height,
+      setup_drawpix_texture(ctx, tex, newTex, texIntFormat, width, height,
                             GL_ALPHA, type, pixels);
 
       _mesa_ColorMask(GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE);
@@ -1768,14 +1777,14 @@ _mesa_meta_DrawPixels(GLcontext *ctx,
       _mesa_ProgramLocalParameter4fvARB(GL_FRAGMENT_PROGRAM_ARB, 0,
                                         ctx->Current.RasterColor);
 
-      setup_drawpix_texture(tex, newTex, texIntFormat, width, height,
+      setup_drawpix_texture(ctx, tex, newTex, texIntFormat, width, height,
                             format, type, pixels);
 
       _mesa_DrawArrays(GL_TRIANGLE_FAN, 0, 4);
    }
    else {
       /* Drawing RGBA */
-      setup_drawpix_texture(tex, newTex, texIntFormat, width, height,
+      setup_drawpix_texture(ctx, tex, newTex, texIntFormat, width, height,
                             format, type, pixels);
       _mesa_DrawArrays(GL_TRIANGLE_FAN, 0, 4);
    }
@@ -1923,7 +1932,7 @@ _mesa_meta_Bitmap(GLcontext *ctx,
       _mesa_set_enable(ctx, GL_ALPHA_TEST, GL_TRUE);
       _mesa_AlphaFunc(GL_GREATER, 0.0);
 
-      setup_drawpix_texture(tex, newTex, texIntFormat, width, height,
+      setup_drawpix_texture(ctx, tex, newTex, texIntFormat, width, height,
                             GL_ALPHA, GL_UNSIGNED_BYTE, bitmap8);
 
       _mesa_DrawArrays(GL_TRIANGLE_FAN, 0, 4);