BACKWARDS INCOMPATIBLE CHANGES:

* Using $BASEDIR to pass the location of the repo hasn't worked for a
  while. It has been removed.  Simply cd into the vcs repo before
  running a command.
BUG FIXES:
* .gitignore was being created in subdirectories instead of VCS root.
MINOR CHANGES
* _blackbox_common.sh: Replace change_to_root with change_to_vcs_root
* confidence_test.sh: Added more assertions and tests.

bin/blackbox_register_new_file

@@ -50,9 +50,11 @@ fi
 
 # TODO(tlim): This should be moved to _blackbox_common.sh in a
 # VCS-independent way.
-IGNOREFILE=".${VCS_TYPE}ignore"
+IGNOREFILE="${REPOBASE}/.${VCS_TYPE}ignore"
 if [[ $VCS_TYPE = 'git' ]]; then
-  ignored_file="$(echo "$unencrypted_file" |  sed 's/\([\*\?]\)/\\\1/g' | sed 's/^\([!#]\)/\\\1/')"
+  relfile="$(vcs_relative_path "$unencrypted_file")"
+  relfileb="${relfile/\$\//}"
+  ignored_file="$(echo "${relfileb}" |  sed 's/\([\*\?]\)/\\\1/g' | sed 's/^\([!#]\)/\\\1/')"
   if ! grep -Fsx >/dev/null "$ignored_file" "$IGNOREFILE"; then
     echo "$ignored_file" >>"$IGNOREFILE"
     COMMIT_FILES+=("$IGNOREFILE")