[PATCH] glx: Do not call into Composite if it is disabled.

[Michal Srb]

Otherwise X server crashes if GLX is enabled and Composite disabled. For
example the compIsAlternateVisual function will try to lookup CompScreenPtr
using the CompScreenPrivateKey, but that was never initialized if Composite is
disabled.

Fixes: f84e59a4f4. ("glx: Duplicate relevant fbconfigs for compositing visuals")
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=104993
Signed-off-by: Michal Srb <msrb at suse.com>
---
 glx/glxdricommon.c | 63 +++++++++++++++++++++++++++++-------------------------
 glx/glxscreens.c   | 33 +++++++++++++++++-----------
 2 files changed, 55 insertions(+), 41 deletions(-)

diff --git a/glx/glxdricommon.c b/glx/glxdricommon.c
index a16e72849..8747ef545 100644
--- a/glx/glxdricommon.c
+++ b/glx/glxdricommon.c
@@ -35,6 +35,7 @@
 #include <GL/glxtokens.h>
 #include <GL/internal/dri_interface.h>
 #include <os.h>
+#include "extinit.h"
 #include "glxserver.h"
 #include "glxext.h"
 #include "glxcontext.h"
@@ -183,28 +184,30 @@ createModeFromConfig(const __DRIcoreExtension * core,
     config->config.yInverted = GL_TRUE;
 
 #ifdef COMPOSITE
-    /*
-     * Here we decide what fbconfigs will be duplicated for compositing.
-     * fgbconfigs marked with duplicatedForConf will be reserved for
-     * compositing visuals.
-     * It might look strange to do this decision this late when translation
-     * from a __DRIConfig is already done, but using the __DRIConfig
-     * accessor function becomes worse both with respect to code complexity
-     * and CPU usage.
-     */
-    if (duplicateForComp &&
-        (render_type_is_pbuffer_only(renderType) ||
-         config->config.rgbBits != 32 ||
-         config->config.redBits != 8 ||
-         config->config.greenBits != 8 ||
-         config->config.blueBits != 8 ||
-         config->config.visualRating != GLX_NONE ||
-         config->config.sampleBuffers != 0)) {
-        free(config);
-        return NULL;
-    }
+    if (!noCompositeExtension) {
+        /*
+        * Here we decide what fbconfigs will be duplicated for compositing.
+        * fgbconfigs marked with duplicatedForConf will be reserved for
+        * compositing visuals.
+        * It might look strange to do this decision this late when translation
+        * from a __DRIConfig is already done, but using the __DRIConfig
+        * accessor function becomes worse both with respect to code complexity
+        * and CPU usage.
+        */
+        if (duplicateForComp &&
+            (render_type_is_pbuffer_only(renderType) ||
+            config->config.rgbBits != 32 ||
+            config->config.redBits != 8 ||
+            config->config.greenBits != 8 ||
+            config->config.blueBits != 8 ||
+            config->config.visualRating != GLX_NONE ||
+            config->config.sampleBuffers != 0)) {
+            free(config);
+            return NULL;
+        }
 
-    config->config.duplicatedForComp = duplicateForComp;
+        config->config.duplicatedForComp = duplicateForComp;
+    }
 #endif
 
     return &config->config;
@@ -238,14 +241,16 @@ glxConvertConfigs(const __DRIcoreExtension * core,
     }
 
 #ifdef COMPOSITE
-    /* Duplicate fbconfigs for use with compositing visuals */
-    for (i = 0; configs[i]; i++) {
-        tail->next = createModeFromConfig(core, configs[i], GLX_TRUE_COLOR,
-                                          GL_TRUE);
-        if (tail->next == NULL)
-            continue;
-
-	tail = tail->next;
+    if (!noCompositeExtension) {
+        /* Duplicate fbconfigs for use with compositing visuals */
+        for (i = 0; configs[i]; i++) {
+            tail->next = createModeFromConfig(core, configs[i], GLX_TRUE_COLOR,
+                                            GL_TRUE);
+            if (tail->next == NULL)
+                continue;
+
+            tail = tail->next;
+        }
     }
 #endif
 
diff --git a/glx/glxscreens.c b/glx/glxscreens.c
index 596d972e0..5cd9fcfd4 100644
--- a/glx/glxscreens.c
+++ b/glx/glxscreens.c
@@ -38,6 +38,7 @@
 #include <os.h>
 #include <colormapst.h>
 
+#include "extinit.h"
 #include "privates.h"
 #include "glxserver.h"
 #include "glxutil.h"
@@ -280,10 +281,12 @@ pickFBConfig(__GLXscreen * pGlxScreen, VisualPtr visual)
         if (config->visualID != 0)
             continue;
 #ifdef COMPOSITE
-	/* Use only duplicated configs for compIsAlternateVisuals */
-        if (!!compIsAlternateVisual(pGlxScreen->pScreen, visual->vid) !=
-	    !!config->duplicatedForComp)
-            continue;
+        if (!noCompositeExtension) {
+            /* Use only duplicated configs for compIsAlternateVisuals */
+            if (!!compIsAlternateVisual(pGlxScreen->pScreen, visual->vid) !=
+                !!config->duplicatedForComp)
+                continue;
+        }
 #endif
         /*
          * If possible, use the same swapmethod for all built-in visual
@@ -353,8 +356,10 @@ __glXScreenInit(__GLXscreen * pGlxScreen, ScreenPtr pScreen)
             pGlxScreen->visuals[pGlxScreen->numVisuals++] = config;
             config->visualID = visual->vid;
 #ifdef COMPOSITE
-            if (compIsAlternateVisual(pScreen, visual->vid))
-                config->visualSelectGroup++;
+            if (!noCompositeExtension) {
+                if (compIsAlternateVisual(pScreen, visual->vid))
+                    config->visualSelectGroup++;
+            }
 #endif
         }
     }
@@ -376,10 +381,12 @@ __glXScreenInit(__GLXscreen * pGlxScreen, ScreenPtr pScreen)
          */
         depth = config->redBits + config->greenBits + config->blueBits;
 #ifdef COMPOSITE
-	if (config->duplicatedForComp) {
-		depth += config->alphaBits;
-		config->visualSelectGroup++;
-	}
+        if (!noCompositeExtension) {
+            if (config->duplicatedForComp) {
+                    depth += config->alphaBits;
+                    config->visualSelectGroup++;
+            }
+        }
 #endif
         /* Make sure that our FBconfig's depth can actually be displayed
          * (corresponds to an existing visual).
@@ -404,8 +411,10 @@ __glXScreenInit(__GLXscreen * pGlxScreen, ScreenPtr pScreen)
             continue;
 
 #ifdef COMPOSITE
-        if (config->duplicatedForComp)
-	    (void) CompositeRegisterAlternateVisuals(pScreen, &visual->vid, 1);
+        if (!noCompositeExtension) {
+            if (config->duplicatedForComp)
+                (void) CompositeRegisterAlternateVisuals(pScreen, &visual->vid, 1);
+        }
 #endif
         pGlxScreen->visuals[pGlxScreen->numVisuals++] = config;
         initGlxVisual(visual, config);
-- 
2.13.6