Re: [PATCH 5/6] t1500: avoid setting environment variables outside of tests

On Tue, May 10, 2016 at 2:39 PM, Jeff King [off-list ref] wrote:

On Tue, May 10, 2016 at 01:20:54AM -0400, Eric Sunshine wrote:

quoted

diff --git a/t/t1500-rev-parse.sh b/t/t1500-rev-parse.sh

@@ -7,11 +7,13 @@ test_description='test git rev-parse'
      while :
      do
              case "$1" in
              -C) dir="-C $2"; shift; shift ;;
              -b) bare="$2"; shift; shift ;;
+             -g) env="GIT_DIR=$2; export GIT_DIR"; shift; shift ;;

This will expand $2 inside $env, which is later eval'd. So funny things
happen if there are spaces or metacharacters. It looks like you only use
it with short relative paths ("../repo.git", etc), which is OK, but this
would probably break badly if we ever used absolute paths.

I don't know if it's worth worrying about or not. The usual solution is
something like:

  env_git_dir=$2
  env='GIT_DIR=$env_git_dir; export GIT_DIR'
  ...
  eval "$env"

Makes sense; I wasn't quite happy with having $2 interpolated
unquoted. Like you, though, I don't know if it's worth worrying
about...

quoted

@@ -36,6 +38,8 @@ test_rev_parse () {
      do
              expect="$1"
              test_expect_success "$name: $o" '
+                     test_when_finished "sane_unset GIT_DIR" &&
+                     eval $env &&

I was surprised not to see quoting around $env here, but it probably
doesn't matter (I think it may affect how some whitespace is treated,
but the contents of $env are pretty tame).

I flip-flopped on this one several times, quoting, and not quoting.
Documentation for 'eval' says:

    The args are read and concatenated together into a single
    command.

so, I ultimately left it unquoted, but don't feel strongly about it.

This will set up the sane_unset regardless of whether $env does
anything. Would it make more sense to stick the test_when_finished
inside $env? You could use regular unset then, too, since you know the
variable would be set.

I didn't worry about it too much because the end result is effectively
the same and, with all the 'case' arms being short one-liners, I think
the code is a bit easier to read as-is; bundling 'test_when_finished'
into the 'env' assignment line would probably require wrapping the
line. I do like the improved encapsulation of your suggestion but
don't otherwise feel strongly about it.

Nevertheless, I can re-roll with these changes if you feel more
strongly than I about it.