Fix crash in xf86InitOrigins()

In a multihead setup, if only the first screen can be
initialized, but the second screen is mentioned first in the
ServerLayout section, the xf86InitOrigins() function will crash
because the screen referred to in the e.g. "RightOf" part is
non-existent.

1 files changed, 8 insertions, 0 deletions

diff --git a/hw/xfree86/common/xf86Cursor.c b/hw/xfree86/common/xf86Cursor.c
index 9e6e62216..3ea1b4d91 100644
--- a/hw/xfree86/common/xf86Cursor.c
+++ b/hw/xfree86/common/xf86Cursor.c
@@ -558,6 +558,14 @@ xf86InitOrigins(void)
 
 	    screen = &xf86ConfigLayout.screens[i];
 
+	    if (screen->refscreen != NULL &&
+		screen->refscreen->screennum >= xf86NumScreens) {
+		screensLeft &= ~(1 << i);
+	        xf86Msg(X_WARNING, "Not including screen \"%s\" in origins calculation.\n",
+			screen->screen->id);
+	        continue;
+	    }
+
 	    switch(screen->where) {
 	    case PosObsolete:
 		OldStyleConfig = TRUE;