mesa: fix assertion failure for GL_ALPHA FBOs

diff --git a/src/mesa/main/framebuffer.c b/src/mesa/main/framebuffer.c
index 01f84180af730a258fb5b3950a4c938176639494..56558cfcc1edf43de3b7b247f0343edcd009c217 100644 (file)
--- a/src/mesa/main/framebuffer.c
+++ b/src/mesa/main/framebuffer.c
@@ -879,6 +879,7 @@ _mesa_source_buffer_exists(GLcontext *ctx, GLenum format)
          return GL_FALSE;
       }
       ASSERT(_mesa_get_format_bits(ctx->ReadBuffer->_ColorReadBuffer->Format, GL_RED_BITS) > 0 ||
+             _mesa_get_format_bits(ctx->ReadBuffer->_ColorReadBuffer->Format, GL_ALPHA_BITS) > 0 ||
              _mesa_get_format_bits(ctx->ReadBuffer->_ColorReadBuffer->Format, GL_INDEX_BITS) > 0);
       break;
    case GL_DEPTH: