[Mesa-dev] [PATCH] mesa: fix glGetFramebufferAttachmentParameteriv w/ on-demand FRONT_BACK alloc

[Marek Olšák]

From: Marek Olšák <marek.olsak at amd.com>

This fixes 66 CTS tests on st/mesa.

Cc: 12.0 <mesa-stable at lists.freedesktop.org>
---
 src/mesa/main/fbobject.c | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/src/mesa/main/fbobject.c b/src/mesa/main/fbobject.c
index 2c01526..09da6b7 100644
--- a/src/mesa/main/fbobject.c
+++ b/src/mesa/main/fbobject.c
@@ -296,23 +296,35 @@ _mesa_get_fb0_attachment(struct gl_context *ctx, struct gl_framebuffer *fb,
          return &fb->Attachment[BUFFER_FRONT_LEFT];
       case GL_DEPTH:
       return &fb->Attachment[BUFFER_DEPTH];
       case GL_STENCIL:
          return &fb->Attachment[BUFFER_STENCIL];
       }
    }
 
    switch (attachment) {
    case GL_FRONT_LEFT:
-      return &fb->Attachment[BUFFER_FRONT_LEFT];
+      /* Front buffers can be allocated on the first use, but
+       * glGetFramebufferAttachmentParameteriv must work even if that
+       * allocation hasn't happened yet. In such case, use the back buffer,
+       * which should be the same.
+       */
+      if (fb->Attachment[BUFFER_FRONT_LEFT].Type == GL_NONE)
+         return &fb->Attachment[BUFFER_BACK_LEFT];
+      else
+         return &fb->Attachment[BUFFER_FRONT_LEFT];
    case GL_FRONT_RIGHT:
-      return &fb->Attachment[BUFFER_FRONT_RIGHT];
+      /* Same as above. */
+      if (fb->Attachment[BUFFER_FRONT_RIGHT].Type == GL_NONE)
+         return &fb->Attachment[BUFFER_BACK_RIGHT];
+      else
+         return &fb->Attachment[BUFFER_FRONT_RIGHT];
    case GL_BACK_LEFT:
       return &fb->Attachment[BUFFER_BACK_LEFT];
    case GL_BACK_RIGHT:
       return &fb->Attachment[BUFFER_BACK_RIGHT];
    case GL_AUX0:
       if (fb->Visual.numAuxBuffers == 1) {
          return &fb->Attachment[BUFFER_AUX0];
       }
       return NULL;
 
-- 
2.7.4