Collected a few ideas for releng_check_isocontent

releng/releng_check_isocontent

@@ -4,4 +4,25 @@ set -e
 
 printf "NOT COMPLETED YET\n"
 
+
+# xorriso provides built-in means for comparison: 
+#  -compare_r disk_path iso_rr_path
+# Possibly i will have to enhance it so that it is suitable for automatic
+# testing. (I used it mainly for testing -update_r.)
+
+# xorriso could use 
+#   -osirrox on -extract iso_rr_path disk_path
+# to pull a tree out of the image without mounting it.
+
+# One could mount the image -o loop. (Needs superuser authority.)
+
+# There is a program test/compare_file which acts on a mounted image
+# or on extracted trees i.e. completely independent of xorriso code.
+# See libisoburn/README paragraph "Testing".
+# With extracted trees one will want to use option -no_ctime.
+
+# One may use command diff -r to compare directory trees of a mounted image
+# or extracted trees.
+
+
 exit 0