Tweak handling of {udeb,base}_{include,exclude} files so multi-arch

builds should work better. Closes: #703436

debian/changelog

@@ -8,6 +8,10 @@ debian-cd (3.1.13) UNRELEASED; urgency=low
   * Allow for override of distro name etc. in grub.cfg for EFI boot too.
     Closes: #705610
 
+  [ Steve McIntyre ]
+  * Tweak handling of {udeb,base}_{include,exclude} files so multi-arch
+    builds should work better. Closes: #703436
+
  -- Raphaël Hertzog <hertzog@debian.org>  Fri, 12 Apr 2013 10:32:56 +0200
 
 debian-cd (3.1.12) unstable; urgency=low

tools/start_new_disc

@@ -77,6 +77,27 @@ else
     export VOLID="$VOLID_BASE M-A $DISKNUM"
 fi
 
+merge_include_exclude () {
+    OUT="$1"
+    TYPE="$2"
+    LIST="$3"
+    WRITE=0 # Don't create empty files
+
+    # Check to see if any file specified actually exist
+    for FILE in $LIST ; do
+        if [ -r "$FILE" ] ; then
+            WRITE=1
+        else
+            echo "WARNING: Unable to read $TYPE file $FILE"
+        fi
+    done
+
+    # If we have any files, merge and write them out
+    if [ "$WRITE" = 1 ] ; then
+        sort -u $LIST > "$OUT"
+    fi
+}
+
 mkdir -p $CDDIR
 echo "  Adding the required directories"
 
@@ -198,40 +219,19 @@ if [ $DISKNUM = 1 ] ; then
                 esac
             fi
 
-            # Sort out the udeb include and exclude files
-            if [ -n "$UDEB_INCLUDE" ] ; then
-                if [ -r "$UDEB_INCLUDE" ] ; then
-                    cat "$UDEB_INCLUDE" >> "$CDDIR/.disk/udeb_include"
-                else
-                    echo "WARNING: Unable to read UDEB_INCLUDE file $UDEB_INCLUDE"
-                fi
-            fi
-            if [ -n "$UDEB_EXCLUDE" ] ; then
-                if [ -r "$UDEB_EXCLUDE" ] ; then
-                    cat "$UDEB_EXCLUDE" >> "$CDDIR/.disk/udeb_exclude"
-                else
-                    echo "WARNING: Unable to read UDEB_EXCLUDE file $UDEB_EXCLUDE"
-                fi
-            fi
-
-            # Ditto the base include and exclude
-            if [ -n "$BASE_INCLUDE" ] ; then
-                if [ -r "$BASE_INCLUDE" ] ; then
-                    cat "$BASE_INCLUDE" >> "$CDDIR/.disk/base_include"
-                else
-                    echo "WARNING: Unable to read BASE_INCLUDE file $BASE_INCLUDE"
-                fi
-            fi
-            if [ -n "$BASE_EXCLUDE" ] ; then
-                if [ -r "$BASE_EXCLUDE" ] ; then
-                    cat "$BASE_EXCLUDE" >> "$CDDIR/.disk/base_exclude"
-                else
-                    echo "WARNING: Unable to read BASE_EXCLUDE file $BASE_EXCLUDE"
-                fi
-            fi
+            UDEB_INCLUDES="$UDEB_INCLUDES $UDEB_INCLUDE"
+            UDEB_EXCLUDES="$UDEB_EXCLUDES $UDEB_EXCLUDE"
+            BASE_INCLUDES="$BASE_INCLUDES $BASE_INCLUDE"
+            BASE_EXCLUDES="$BASE_EXCLUDES $BASE_EXCLUDE"
         fi
     done
 
+    # Sort and merge the the include and exclude files as necessary
+    merge_include_exclude "$CDDIR/.disk/udeb_include" UDEB_INCLUDE "$UDEB_INCLUDES"
+    merge_include_exclude "$CDDIR/.disk/udeb_exclude" UDEB_EXCLUDE "$UDEB_EXCLUDES"
+    merge_include_exclude "$CDDIR/.disk/base_include" BASE_INCLUDE "$BASE_INCLUDES"
+    merge_include_exclude "$CDDIR/.disk/base_exclude" BASE_EXCLUDE "$BASE_EXCLUDES"
+
     if [ "$OMIT_DOC_TOOLS" != "1" ]; then
         echo "  Adding docs to CD1"
         $BASEDIR/tools/add_files $CDDIR $MIRROR doc