Fix inverted condition for `--altinstall` of ensurepip (#255)

plugins/python-build/bin/python-build

@@ -1528,10 +1528,12 @@ build_package_get_pip() {
 
 build_package_ensurepip() {
   local ensurepip_opts
-  if [[ "$PYTHON_MAKE_INSTALL_TARGET" != *"altinstall"* ]]; then
+  # Install as `--altinstall` if the Python is installed as `altinstall` (#255)
+  if [[ "$PYTHON_MAKE_INSTALL_TARGET" == *"altinstall"* ]]; then
     ensurepip_opts="--altinstall"
   fi
-  "$PYTHON_BIN" -m ensurepip $ensurepip_opts 1>/dev/null 2>&1 || build_package_get_pip "$@" || return 1
+  # FIXME: `--altinstall` with `get-pip.py`
+  "$PYTHON_BIN" -m ensurepip ${ensurepip_opts} 1>/dev/null 2>&1 || build_package_get_pip "$@" || return 1
 }
 
 version() {

plugins/python-build/test/pyenv_ext.bats

@@ -159,3 +159,39 @@ OUT
 
   unstub make
 }
+
+@test "ensurepip without altinstall" {
+  mkdir -p "${INSTALL_ROOT}/bin"
+  cat <<OUT > "${INSTALL_ROOT}/bin/python"
+#!$BASH
+echo "python \$@" >> "${INSTALL_ROOT}/build.log"
+OUT
+  chmod +x "${INSTALL_ROOT}/bin/python"
+
+  PYTHON_MAKE_INSTALL_TARGET="" TMPDIR="$TMP" run_inline_definition <<OUT
+build_package_ensurepip
+OUT
+  assert_success
+
+  assert_build_log <<OUT
+python -m ensurepip
+OUT
+}
+
+@test "ensurepip with altinstall" {
+  mkdir -p "${INSTALL_ROOT}/bin"
+  cat <<OUT > "${INSTALL_ROOT}/bin/python"
+#!$BASH
+echo "python \$@" >> "${INSTALL_ROOT}/build.log"
+OUT
+  chmod +x "${INSTALL_ROOT}/bin/python"
+
+  PYTHON_MAKE_INSTALL_TARGET="altinstall" TMPDIR="$TMP" run_inline_definition <<OUT
+build_package_ensurepip
+OUT
+  assert_success
+
+  assert_build_log <<OUT
+python -m ensurepip --altinstall
+OUT
+}