Backport more fixes for stable builds:

+ Fix code extracting the xorriso version.
    + tools/apt-selection: pass APT::Architectures:: when calling apt;
      otherwise if we're running on a multi-arch system apt will break
    + Factor out the xorriso version-checking code

debian/changelog

@@ -8,6 +8,10 @@ debian-cd (3.1.13-deb7u1) UNRELEASED; urgency=low
       now instead of in Index, apparently.
     + Add "UEFI" text to the UEFI installer menu title to make it easier for
       end users to distinguish between UEFI and BIOS boot.
+    + Fix code extracting the xorriso version.
+    + tools/apt-selection: pass APT::Architectures:: when calling apt;
+      otherwise if we're running on a multi-arch system apt will break
+    + Factor out the xorriso version-checking code
 
  -- Steve McIntyre <93sam@debian.org>  Mon, 17 June 2013 15:44:32 +0100
 

tools/apt-selection

@@ -34,6 +34,7 @@ options=" -q -o Dir::State::status=$APTTMP/$CODENAME-$ARCH/status \
 		  -o APT::Cache::AllVersions=0 \
 		  -o APT::Cache::ShowVersion=1 \
 		  -o APT::Architecture=$ARCH \
+                  -o APT::Architectures::=$ARCH \
 		  -o Acquire::Languages=none"
 
 sections=main

tools/boot/wheezy/boot-x86

@@ -37,12 +37,7 @@ fi
 
 case "$MKISOFS" in
     *xorriso*)
-        XORRISO_VER=$($MKISOFS --version 2>&1 | awk '
+        XORRISO_VER=$(xorriso_version)
-            NR==1 {
-                 split($3, ver, ".")
-                 print ver[1]*10000+ver[2]*100+ver[3]
-            }')
-        # OK
         ;;
     *)
 	echo "ERROR: debian-cd now depends on xorriso for making x86 bootable CDs."

tools/boot/wheezy/common.sh

@@ -92,3 +92,12 @@ calc_boot_size() {
     size=$[($(stat -c%s "$FILE")+2047)/2048]
     echo $size
 }
+
+# Grab the xorriso version and turn it into a number we can use
+xorriso_version() {
+    $MKISOFS --version 2>&1 | awk '
+       `/^xorriso version/ {
+           split($4, ver, ".")
+           print ver[1]*10000+ver[2]*100+ver[3]
+       }'
+}