classes/base: fix license file checksumming when source not under TMPDIR

With the changes to the code for extracting source for a recipe, we are
properly executing the tasks for a recipe, which means their stamps (and
therefore signatures) are important. When running devtool extract on
the lsof recipe I noticed that do_fetch and do_unpack were executing a
second time when we called for do_patch, and this turned out to be
because LIC_FILES_CHKSUM in that recipe contains an entry which
is an absolute path (has ${S} at the start). Normally this wouldn't be
an issue since S is under TMPDIR and thus the existing code would ignore
it, however devtool's extraction code extracts to a temporary directory
which is not under TMPDIR; the result was the path to this file was not
being ignored and the second time around when the license file had been
extracted it was incorporated into the signature. We don't want this, so
explicitly exclude S as well as B and WORKDIR for good measure.

(From OE-Core rev: 1c99d74a862f25e23ea6465fab7ddc9ce74d6974)

Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/classes/base.bbclass

@@ -98,6 +98,9 @@ def get_lic_checksum_file_list(d):
     filelist = []
     lic_files = d.getVar("LIC_FILES_CHKSUM", True) or ''
     tmpdir = d.getVar("TMPDIR", True)
+    s = d.getVar("S", True)
+    b = d.getVar("B", True)
+    workdir = d.getVar("WORKDIR", True)
 
     urls = lic_files.split()
     for url in urls:
@@ -109,7 +112,7 @@ def get_lic_checksum_file_list(d):
                 raise bb.fetch.MalformedUrl(url)
 
             if path[0] == '/':
-                if path.startswith(tmpdir):
+                if path.startswith((tmpdir, s, b, workdir)):
                     continue
                 filelist.append(path + ":" + str(os.path.exists(path)))
         except bb.fetch.MalformedUrl: