[Mesa-dev] [PATCH] st: Allow accelerated CopyTexImage from RGBA to RGB.

[Eric Anholt]

There's nothing to worry about here -- the A channel just gets dropped by
the blit.  This avoids a segfault in the fallback path when copying from a
RGBA16_SINT renderbuffer to a RGB16_SINT destination represented by an
RGBA16_SINT texture (the fallback path tries to get/fetch to float
buffers, but the float pack/unpack functions are NULL for SINT/UINT).

Fixes KHR-GLES3.packed_pixels.pbo_rectangle.rgba16i on VC5.
---
 src/mesa/state_tracker/st_cb_texture.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/mesa/state_tracker/st_cb_texture.c b/src/mesa/state_tracker/st_cb_texture.c
index 6345ead6396b..469a82a75390 100644
--- a/src/mesa/state_tracker/st_cb_texture.c
+++ b/src/mesa/state_tracker/st_cb_texture.c
@@ -2327,8 +2327,10 @@ st_CopyTexSubImage(struct gl_context *ctx, GLuint dims,
    /* The base internal format must match the mesa format, so make sure
     * e.g. an RGB internal format is really allocated as RGB and not as RGBA.
     */
-   if (texImage->_BaseFormat !=
-       _mesa_get_format_base_format(texImage->TexFormat) ||
+   if ((texImage->_BaseFormat !=
+        _mesa_get_format_base_format(texImage->TexFormat) &&
+        (texImage->_BaseFormat != GL_RGB ||
+         _mesa_get_format_base_format(texImage->TexFormat) != GL_RGBA)) ||
        rb->_BaseFormat != _mesa_get_format_base_format(rb->Format)) {
       goto fallback;
    }
-- 
2.16.2