From 2b425ad61c9376b49a7709d26c045fb5b73e9142 Mon Sep 17 00:00:00 2001
From: Henning Geinitz <sane@geinitz.org>
Date: Sun, 22 Jan 2006 16:52:13 +0000
Subject: [PATCH] Added checks for altsetting =! 0.

---
 ChangeLog                 |  2 ++
 sanei/sanei_usb.c         | 13 +++++++++++--
 tools/sane-find-scanner.c |  3 +++
 3 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 00ca59de6..3308085af 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -5,6 +5,8 @@
 	  <olaf@member.fsf.org>). 
 	* doc/descriptions/unsupported.desc: Added Scanshell 800N and
 	  Canon Smartbase MP360.
+	* sanei/sanei_usb.c tools/sane-find-scanner.c: Added checks for
+	  altsetting =! 0.
 
 2006-01-22  Mattias Ellert <mattias.ellert@tsl.uu.se>
 
diff --git a/sanei/sanei_usb.c b/sanei/sanei_usb.c
index 867d40e3a..34a27e539 100644
--- a/sanei/sanei_usb.c
+++ b/sanei/sanei_usb.c
@@ -459,6 +459,15 @@ sanei_usb_init (void)
 		  found = SANE_TRUE;
 		  break;
 		case USB_CLASS_PER_INTERFACE:
+		  if (dev->config[0].interface[interface].num_altsetting == 0 || 
+		      !dev->config[0].interface[interface].altsetting)
+		    {
+		      DBG (1, "sanei_usb_init: device 0x%04x/0x%04x doesn't "
+			   "have an altsetting for interface %d\n",
+			   dev->descriptor.idVendor, dev->descriptor.idProduct,
+			   interface);
+		      continue;
+		    }
 		  switch (dev->config[0].interface[interface].altsetting[0].
 			  bInterfaceClass)
 		    {
@@ -476,8 +485,8 @@ sanei_usb_init (void)
 		     "scanner (%d/%d)\n", dev->descriptor.idVendor,
 		     dev->descriptor.idProduct, interface,
 		     dev->descriptor.bDeviceClass,
-		     dev->config[0].interface[interface].altsetting[0].
-		     bInterfaceClass);
+		     dev->config[0].interface[interface].altsetting != 0 ? dev->config[0].interface[interface].altsetting[0].
+		     bInterfaceClass : -1);
 	    }
 	  interface--;
 	  if (!found)
diff --git a/tools/sane-find-scanner.c b/tools/sane-find-scanner.c
index 24eac8944..372e3b605 100644
--- a/tools/sane-find-scanner.c
+++ b/tools/sane-find-scanner.c
@@ -625,6 +625,9 @@ check_libusb_device (struct usb_device *dev, SANE_Bool from_file)
 	  ++is_scanner;
 	  break;
 	case USB_CLASS_PER_INTERFACE:
+	  if (dev->config[0].interface[interface_nr].num_altsetting == 0 || 
+	      !dev->config[0].interface[interface_nr].altsetting)
+	    break;
 	  switch (dev->config[0].interface[interface_nr].altsetting[0].bInterfaceClass)
 	    {
 	    case USB_CLASS_VENDOR_SPEC: