From eff25430b4a391409e39337962ff7697165d23c7 Mon Sep 17 00:00:00 2001
From: Daniel Drake <dsd@laptop.org>
Date: Thu, 24 Jul 2008 21:06:34 -0500
Subject: [PATCH] Don't abort if swrast library is not present

GLX is enabled by default, but the current swrast behaviour causes X
to abort with fatal error if the swrast dri library dlopen fails.

Handle the case where the swrast library is not present, and do not
register the GLX extension unless at least one screen has a usable
GL provider.
---
 glx/glxdriswrast.c |    2 +-
 glx/glxext.c       |   37 ++++++++++++++++++++++++-------------
 2 files changed, 25 insertions(+), 14 deletions(-)

diff --git a/glx/glxdriswrast.c b/glx/glxdriswrast.c
index 199f5f8..2859704 100644
--- a/glx/glxdriswrast.c
+++ b/glx/glxdriswrast.c
@@ -515,7 +515,7 @@ __glXDRIscreenProbe(ScreenPtr pScreen)
 
     xfree(screen);
 
-    FatalError("GLX: could not load software renderer\n");
+    LogMessage(X_ERROR, "GLX: could not load software renderer\n");
 
     return NULL;
 }
diff --git a/glx/glxext.c b/glx/glxext.c
index 13c65da..6ba404f 100644
--- a/glx/glxext.c
+++ b/glx/glxext.c
@@ -279,6 +279,7 @@ void GlxExtensionInit(void)
     ScreenPtr pScreen;
     int i;
     __GLXprovider *p;
+    Bool glx_provided = False;
 
     __glXContextRes = CreateNewResourceType((DeleteType)ContextGone);
     __glXDrawableRes = CreateNewResourceType((DeleteType)DrawableGone);
@@ -289,6 +290,29 @@ void GlxExtensionInit(void)
     if (!AddCallback (&ClientStateCallback, glxClientCallback, 0))
 	return;
 
+    for (i = 0; i < screenInfo.numScreens; i++) {
+	pScreen = screenInfo.screens[i];
+
+	for (p = __glXProviderStack; p != NULL; p = p->next) {
+	    if (p->screenProbe(pScreen) != NULL) {
+		LogMessage(X_INFO,
+			   "GLX: Initialized %s GL provider for screen %d\n",
+			   p->name, i);
+		break;
+	    }
+	}
+
+	if (!p)
+	    LogMessage(X_INFO,
+		       "GLX: no usable GL providers found for screen %d\n", i);
+	else
+	    glx_provided = True;
+    }
+
+    /* don't register extension if GL is not provided on any screen */
+    if (!glx_provided)
+	return;
+
     /*
     ** Add extension to server extensions.
     */
@@ -306,19 +330,6 @@ void GlxExtensionInit(void)
     }
 
     __glXErrorBase = extEntry->errorBase;
-
-    for (i = 0; i < screenInfo.numScreens; i++) {
-	pScreen = screenInfo.screens[i];
-
-	for (p = __glXProviderStack; p != NULL; p = p->next) {
-	    if (p->screenProbe(pScreen) != NULL) {
-		LogMessage(X_INFO,
-			   "GLX: Initialized %s GL provider for screen %d\n",
-			   p->name, i);
-	    	break;
-	    }
-	}
-    }
 }
 
 /************************************************************************/
-- 
1.5.5.1