commit 4da6cffa8b6169595ea447cc53dfab857c04db04
Author: h_root <root@hilbert.suse.de>
Date:   Thu Mar 25 18:32:04 2010 +0100

    when doing driver autoconfiguration with some parts of the config
    file present but no driver set (e.g. only input configuration)
    fix the case that we may have multiple drivers to try.
    
    create a screen section for each driver and let them be tried
    in a row

diff --git a/hw/xfree86/common/xf86AutoConfig.c b/hw/xfree86/common/xf86AutoConfig.c
index 7f4ada8..56f7deb 100644
--- a/hw/xfree86/common/xf86AutoConfig.c
+++ b/hw/xfree86/common/xf86AutoConfig.c
@@ -546,10 +546,41 @@ chooseVideoDriver(void)
     return chosen_driver;
 }
 
+
+/* copy a screen section and enter the desired driver
+ * and insert it at i in the list of screens */
+static Bool
+copyScreen(confScreenPtr oscreen, GDevPtr odev, int i, char *driver)
+{
+    GDevPtr cptr = NULL;
+
+    xf86ConfigLayout.screens[i].screen = xnfcalloc(1, sizeof(confScreenRec));
+    if(!xf86ConfigLayout.screens[i].screen)
+        return FALSE;
+    memcpy(xf86ConfigLayout.screens[i].screen, oscreen, sizeof(confScreenRec));
+
+    cptr = xcalloc(1, sizeof(GDevRec));
+    if (!cptr)
+        return FALSE;
+    memcpy(cptr, odev, sizeof(GDevRec));
+
+    cptr->identifier = Xprintf("Autoconfigured Video Device %s", driver);
+    cptr->driver = driver;
+
+    /* now associate the new driver entry with the new screen entry */
+    xf86ConfigLayout.screens[i].screen->device = cptr;
+    cptr->myScreenSection = xf86ConfigLayout.screens[i].screen;
+
+    return TRUE;
+}
+
 GDevPtr
 autoConfigDevice(GDevPtr preconf_device)
 {
     GDevPtr ptr = NULL;
+    char *matches[20]; /* If we have more than 20 drivers we're in trouble */
+    int num_matches = 0, num_screens = 0, i;
+    screenLayoutPtr slp;
 
     if (!xf86configptr) {
         return NULL;
@@ -573,14 +604,59 @@ autoConfigDevice(GDevPtr preconf_device)
         ptr->driver = NULL;
     }
     if (!ptr->driver) {
-        ptr->driver = chooseVideoDriver();
-    }
+        /* get all possible video drivers and count them */
+        listPossibleVideoDrivers(matches, 20);
+        for (; matches[num_matches]; num_matches++) {
+            xf86Msg(X_DEFAULT, "Matched %s as autoconfigured driver %d\n",
+                    matches[num_matches], num_matches);
+        }
+
+        slp = xf86ConfigLayout.screens;
+        if (slp) {
+            /* count the number of screens and make space for
+             * a new screen for each additional possible driver
+             * minus one for the already existing first one
+             * plus one for the terminating NULL */
+            for (; slp[num_screens].screen; num_screens++);
+            xf86ConfigLayout.screens = xnfcalloc(num_screens + num_matches,
+                                                sizeof(screenLayoutRec));
+            xf86ConfigLayout.screens[0] = slp[0];
+
+            /* do the first match and set that for the original first screen */
+            ptr->driver = matches[0];
+            if (!xf86ConfigLayout.screens[0].screen->device) {
+                xf86ConfigLayout.screens[0].screen->device = ptr;
+                ptr->myScreenSection = xf86ConfigLayout.screens[0].screen;
+            }
+
+            /* for each other driver found, copy the first screen, insert it
+             * into the list of screens and set the driver */
+            i = 0;
+            while (i++ < num_matches) {
+                if (!copyScreen(slp[0].screen, ptr, i, matches[i]))
+                    return NULL;
+            }
 
-    /* TODO Handle multiple screen sections */
-    if (xf86ConfigLayout.screens && !xf86ConfigLayout.screens->screen->device) {
-        xf86ConfigLayout.screens->screen->device = ptr;
-        ptr->myScreenSection = xf86ConfigLayout.screens->screen;
+            /* shift the rest of the original screen list
+             * to the end of the current screen list
+             *
+             * TODO Handle rest of multiple screen sections */
+            for (i = 1; i < num_screens; i++) {
+                xf86ConfigLayout.screens[i+num_matches] = slp[i];
+            }
+            xf86ConfigLayout.screens[num_screens+num_matches-1].screen = NULL;
+            xfree(slp);
+        } else {
+            /* layout does not have any screens, not much to do */
+            ptr->driver = matches[0];
+            for (i = 1; matches[i] ; i++) {
+                if (matches[i] != matches[0]) {
+                    xfree(matches[i]);
+                }
+            }
+        }
     }
+
     xf86Msg(X_DEFAULT, "Assigned the driver to the xf86ConfigLayout\n");
 
     return ptr;