From 8b64b35506ff68539e03ea3230214b7dba81dcf3 Mon Sep 17 00:00:00 2001 From: Carl Worth Date: Tue, 19 Feb 2013 16:21:33 -0800 Subject: [PATCH] i965: Avoid segfault in gen6_upload_state This fixes a bug introduced in commit 258453716f001eab1288d99765213 and triggered whenever "rb" is NULL. Fixes bug #59445: [SNB/IVB/HSW Bisected]Oglc draw-buffers2(advanced.blending.none) segfault https://bugs.freedesktop.org/show_bug.cgi?id=59445 --- I don't know under what conditions "rb" might be NULL, but it's clear that it's possible and expected as there is earlier code in this function that checks it, (and sets rb_type specifically in that case). So if someone could help me write a more descriptive commit message, that would be great. Also, I notice that similar code in brw_cc.c uses a different condition here: if (ctx->DrawBuffer->Visual.alphaBits == 0) { So an alternate fix could be to switch to something like that. Please let me know if one version or the other is cleaner, (and both could be made to match). src/mesa/drivers/dri/i965/gen6_cc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/src/mesa/drivers/dri/i965/gen6_cc.c b/src/mesa/drivers/dri/i965/gen6_cc.c index d32f636..7ac5d5f 100644 --- a/src/mesa/drivers/dri/i965/gen6_cc.c +++ b/src/mesa/drivers/dri/i965/gen6_cc.c @@ -126,7 +126,7 @@ gen6_upload_blend_state(struct brw_context *brw) * not read the alpha channel, but will instead use the correct * implicit value for alpha. */ - if (!_mesa_base_format_has_channel(rb->_BaseFormat, GL_TEXTURE_ALPHA_TYPE)) + if (rb && !_mesa_base_format_has_channel(rb->_BaseFormat, GL_TEXTURE_ALPHA_TYPE)) { srcRGB = brw_fix_xRGB_alpha(srcRGB); srcA = brw_fix_xRGB_alpha(srcA); -- 1.7.10.4