bitbake: Provide LAYERDIR_RE for layer.conf

This variable is a regex-escaped version of LAYERDIR, for safer use in
BBFILE_PATTERN, so as to avoid issues with regex special characters in the
layer path.

[YOCTO #8402]

(Bitbake rev: 72900522778b6ff08b135bf8bb97dff3f1a20bd9)

Signed-off-by: Christopher Larson <chris_larson@mentor.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/bb/cookerdata.py

@@ -22,9 +22,11 @@
 # with this program; if not, write to the Free Software Foundation, Inc.,
 # 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 
-import os, sys
-from functools import wraps
 import logging
+import os
+import re
+import sys
+from functools import wraps
 import bb
 from bb import data
 import bb.parse
@@ -296,9 +298,12 @@ class CookerDataBuilder(object):
                 if layer.endswith('/'):
                     layer = layer.rstrip('/')
                 data.setVar('LAYERDIR', layer)
+                data.setVar('LAYERDIR_RE', re.escape(layer))
                 data = parse_config_file(os.path.join(layer, "conf", "layer.conf"), data)
                 data.expandVarref('LAYERDIR')
+                data.expandVarref('LAYERDIR_RE')
 
+            data.delVar('LAYERDIR_RE')
             data.delVar('LAYERDIR')
 
         if not data.getVar("BBPATH", True):