Fix isoinfo usage in the iso9660 view action

- ensure the "natural" Rock Ridge -> Joliet -> ECMA-119 fallback order
- never try -J when the iso has no Joliet stuff
- do not mix -R and -J together

Author: slowpeek

misc/ext.d/misc.sh.in

@@ -13,11 +13,54 @@ do_view_action() {
 
     case "${filetype}" in
     iso9660)
-         if which isoinfo > /dev/null 2>&1; then
-             isoinfo -d -i "${MC_EXT_FILENAME}" && isoinfo -l -R -J -i "${MC_EXT_FILENAME}"
-         else
-             7za l "${MC_EXT_FILENAME}"
-         fi
+        if which isoinfo > /dev/null 2>&1; then
+            info=$(isoinfo -d -i "${MC_EXT_FILENAME}")
+            _st=$?
+
+            if [ "$_st" = 0 ]; then
+                # Prepend the listing with `isoinfo -d` output
+                echo "$info"
+
+                echo "$info" | {
+                    rock=n
+                    joliet=n
+
+                    while read -r line; do
+                        case "$line" in
+                            Rock*found)
+                                rock=y ;;
+                            Joliet*found)
+                                joliet=y ;;
+                        esac
+                    done
+
+                    # Contrary to xorriso, isoinfo does not assume the "natural"
+                    # Rock Ridge -> Joliet -> ECMA-119 fallback order. Without
+                    # any options it uses ECMA-119. With -R it uses Rock Ridge,
+                    # if present, with a fallback to ECMA-119. With -J it uses
+                    # Joliet, if present, but throws an error otherwise. When
+                    # both -J and -R are set (regardless the order), -R is
+                    # ignored. Hence, there is no point in using both together
+                    # in the sense of "either of the two".
+
+                    ext=
+                    if [ $rock = y ]; then
+                        ext=-R
+                    elif [ $joliet = y ]; then
+                        ext=-J
+                    fi
+
+                    # `isoinfo -l` should be the last command to transfer its
+                    # status to the pipe
+                    isoinfo -l $ext -i "${MC_EXT_FILENAME}"
+                } || _st=$?
+            fi
+
+            # Set status as if it was `isoinfo -d .. && isoinfo -l ..` one-liner
+            (exit "$_st")
+        else
+            7za l "${MC_EXT_FILENAME}"
+        fi
         ;;
     cat)
         cat "${MC_EXT_FILENAME}" 2>/dev/null