lib/oeqa/selftest/lic-checksum: Verify failure when checksum changes.

The test added verifies that when a file with an absolute path in
LIC_FILES_CHKSUM changes without a corresponding change to the md5sum,
it triggers the license qa test again with a failure.

[Yocto #6450]

(From OE-Core rev: cab59ce08916c45c1d9da1cf9a92a67574f6c2c3)

Signed-off-by: Randy Witt <randy.e.witt@linux.intel.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta-selftest/recipes-test/emptytest/emptytest.bb

@@ -0,0 +1,5 @@
+include test_recipe.inc
+
+# Set LICENSE to something so that bitbake -p that is ran at the beginning
+# is successful since test_recipe.inc has not yet been modified.
+LICENSE = ""

meta/lib/oeqa/selftest/lic-checksum.py

@@ -0,0 +1,28 @@
+import os
+import tempfile
+
+from oeqa.selftest.base import oeSelfTest
+from oeqa.utils.commands import bitbake
+from oeqa.utils import CommandError
+
+class LicenseTests(oeSelfTest):
+    
+    # Verify that changing a license file that has an absolute path causes
+    # the license qa to fail due to a mismatched md5sum.
+    def test_foo(self):
+        bitbake_cmd = '-c configure emptytest'
+        error_msg = 'ERROR: emptytest: The new md5 checksum is 8d777f385d3dfec8815d20f7496026dc'
+
+        lic_file, lic_path = tempfile.mkstemp()
+        os.close(lic_file)
+        self.track_for_cleanup(lic_path)
+
+        self.write_recipeinc('emptytest', 'LIC_FILES_CHKSUM = "file://%s;md5=d41d8cd98f00b204e9800998ecf8427e"' % lic_path)
+        result = bitbake(bitbake_cmd)
+
+        with open(lic_path, "w") as f:
+            f.write("data")
+
+        result = bitbake(bitbake_cmd, ignore_status=True)
+        if error_msg not in result.output:
+            raise AssertionError(result.output)