Use a better technique for dealing with empty arrays when `set -u`.

https://news.ycombinator.com/item?id=11497636

1 files changed, 2 insertions, 1 deletions

diff --git a/HACKING/code-quality.md b/HACKING/code-quality.md
index a520ce5..8efd561 100644
--- a/HACKING/code-quality.md
+++ b/HACKING/code-quality.md
@@ -49,7 +49,8 @@ Use `set -u` if you can; it makes using an unset variable an error.
  - If a variable not being set is valid (perhaps a configuration
    option), use `${var:-}` when accessing it to suppress the error.
  - An empty array counts as unset, so if you have an array that may be
-   empty, use `set +u` before accessing it.
+   empty, use `${var+"${var[@]}"}` (don't put quotes around the outer
+   pair of braces) to only access it if it's non-empty.
    - The reason for this is that a normal string variable is basically
      an array with length=1; an unset variable looks like an array
      with length=0.  Weird stuff.