tests: add test_join

tests/test_join.sh

+#!/bin/sh
+
+__filter_by_installed_packages()
+{
+    local i
+    local tapt="$1"
+
+    local pkglist
+    pkglist="$(mktemp)" || fatal
+    remove_on_exit $pkglist
+    epm --short packages | sort >$pkglist
+    join -11 -21 $tapt $pkglist
+
+    # get supported packages list and print lines with it
+    #for i in $(epm query --short $(cat $tapt | cut -f1 -d" ") 2>/dev/null) ; do
+    #    grep "^$i " $tapt
+    #done
+}
+
+__filter_by_installed_packages test_join.txt

tests/test_join.txt

+mc mchello
+mc1 mchello1