glib-2.0: replace THISDIR instead of COREBASE in find_meson_cross_files --cross-file paths

* COREBASE works correctly only as long as this recipe is inside of
  COREBASE directory and leaves the full absolute paths if you copy
  this recipe into your own layer (e.g. to backport newer version)

* use THISDIR as all FILESPATH should be relative to that, unless
  there is a .bbappend not only extending FILESPATH, but also adding
  meson.cross.d files there (at which point it also didn't work with
  COREBASE replacements as well already) - show an ERROR in such case,
  I don't think it's common scenario to spend more time to support that.

(From OE-Core rev: 314cfc7d6a8f9b00db7da5424890ff955a5ce971)

Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-core/glib-2.0/glib-2.0_2.66.7.bb

@@ -31,7 +31,7 @@ def find_meson_cross_files(d):
     if bb.data.inherits_class('native', d):
         return ""
 
-    corebase = d.getVar("COREBASE")
+    thisdir = d.getVar("THISDIR")
     import collections
     sitedata = siteinfo_data(d)
     # filename -> found
@@ -39,7 +39,11 @@ def find_meson_cross_files(d):
     for path in d.getVar("FILESPATH").split(":"):
         for element in sitedata:
             filename = os.path.normpath(os.path.join(path, "meson.cross.d", element))
-            files[filename.replace(corebase, "${COREBASE}")] = os.path.exists(filename)
+            sanitized_path = filename.replace(thisdir, "${THISDIR}")
+            if sanitized_path == filename:
+                bb.error("Cannot add '%s' to --cross-file, because it's not relative to THISDIR '%s' and sstate signature would contain this full path" % (filename, thisdir))
+                continue
+            files[filename.replace(thisdir, "${THISDIR}")] = os.path.exists(filename)
 
     items = ["--cross-file=" + k for k,v in files.items() if v]
     d.appendVar("EXTRA_OEMESON", " " + " ".join(items))