Add bud regression tests

We recently made a couple of commits to the imagebuilder
project to address containers#2345 and containers#2192.  Tests were created
in that project, but I thought it best to add some
regression tests here in Buildah too.

FYI: @petr-motejlek and @tachoknight

Signed-off-by: TomSweeneyRedHat <tsweeney@redhat.com>

tests/bud.bats

@@ -2104,3 +2104,15 @@ EOM
   run_buildah --log-level "warn" bud --signature-policy ${TESTSDIR}/policy.json -t test ${TESTSDIR}/bud/build-arg
   expect_output --substring 'missing .+ build argument'
 }
+
+@test "bud arg and env var with same name" {
+  # Regresion test for https://github.com/containers/buildah/issues/2345
+  run_buildah bud --signature-policy ${TESTSDIR}/policy.json -t testctr ${TESTSDIR}/bud/dupe-arg-env-name
+  expect_output --substring "https://example.org/bar"
+}
+
+@test "bud copy chown with newuser" {
+  # Regression test for https://github.com/containers/buildah/issues/2192
+  run_buildah bud --signature-policy ${TESTSDIR}/policy.json -t testctr -f ${TESTSDIR}/bud/copy-chown/Containerfile.chown_user ${TESTSDIR}/bud/copy-chown
+  expect_output --substring "myuser myuser"
+}

tests/bud/copy-chown/Containerfile.chown_user

@@ -0,0 +1,8 @@
+FROM ubuntu:latest
+
+ENV MYUSER=myuser
+
+RUN useradd --create-home --home /"${MYUSER}" "${MYUSER}"
+COPY --chown="${MYUSER}" ./copychown.txt /somewhere
+
+RUN ls -alF /somewhere

tests/bud/dupe-arg-env-name/Containerfile

@@ -0,0 +1,7 @@
+FROM centos:8
+ARG FOO=bar
+ARG WEBROOT=https://example.org/
+
+ENV WEBROOT="$WEBROOT$FOO"
+
+RUN echo "${WEBROOT}"