diff --git a/poky/scripts/lib/checklayer/__init__.py b/poky/scripts/lib/checklayer/__init__.py
index e69a10f..aa946f3 100644
--- a/poky/scripts/lib/checklayer/__init__.py
+++ b/poky/scripts/lib/checklayer/__init__.py
@@ -156,6 +156,27 @@
                 return layer
     return None
 
+def sanity_check_layers(layers, logger):
+    """
+    Check that we didn't find duplicate collection names, as the layer that will
+    be used is non-deterministic. The precise check is duplicate collections
+    with different patterns, as the same pattern being repeated won't cause
+    problems.
+    """
+    import collections
+
+    passed = True
+    seen = collections.defaultdict(set)
+    for layer in layers:
+        for name, data in layer.get("collections", {}).items():
+            seen[name].add(data["pattern"])
+
+    for name, patterns in seen.items():
+        if len(patterns) > 1:
+            passed = False
+            logger.error("Collection %s found multiple times: %s" % (name, ", ".join(patterns)))
+    return passed
+
 def get_layer_dependencies(layer, layers, logger):
     def recurse_dependencies(depends, layer, layers, logger, ret = []):
         logger.debug('Processing dependencies %s for layer %s.' % \
@@ -261,7 +282,7 @@
         raise RuntimeError(msg)
     return output
 
-def get_signatures(builddir, failsafe=False, machine=None):
+def get_signatures(builddir, failsafe=False, machine=None, extravars=None):
     import re
 
     # some recipes needs to be excluded like meta-world-pkgdata
@@ -272,7 +293,10 @@
     sigs = {}
     tune2tasks = {}
 
-    cmd = 'BB_ENV_EXTRAWHITE="$BB_ENV_EXTRAWHITE BB_SIGNATURE_HANDLER" BB_SIGNATURE_HANDLER="OEBasicHash" '
+    cmd = 'BB_ENV_PASSTHROUGH_ADDITIONS="$BB_ENV_PASSTHROUGH_ADDITIONS BB_SIGNATURE_HANDLER" BB_SIGNATURE_HANDLER="OEBasicHash" '
+    if extravars:
+        cmd += extravars
+        cmd += ' '
     if machine:
         cmd += 'MACHINE=%s ' % machine
     cmd += 'bitbake '
diff --git a/poky/scripts/lib/checklayer/cases/common.py b/poky/scripts/lib/checklayer/cases/common.py
index 9f15e05..491a139 100644
--- a/poky/scripts/lib/checklayer/cases/common.py
+++ b/poky/scripts/lib/checklayer/cases/common.py
@@ -54,6 +54,21 @@
         '''
         get_signatures(self.td['builddir'], failsafe=False)
 
+    def test_world_inherit_class(self):
+        '''
+        This also does "bitbake -S none world" along with inheriting "yocto-check-layer"
+        class, which can do additional per-recipe test cases.
+        '''
+        msg = []
+        try:
+            get_signatures(self.td['builddir'], failsafe=False, machine=None, extravars='BB_ENV_PASSTHROUGH_ADDITIONS="$BB_ENV_PASSTHROUGH_ADDITIONS INHERIT" INHERIT="yocto-check-layer"')
+        except RuntimeError as ex:
+            msg.append(str(ex))
+        if msg:
+            msg.insert(0, 'Layer %s failed additional checks from yocto-check-layer.bbclass\nSee below log for specific recipe parsing errors:\n' % \
+                self.tc.layer['name'])
+            self.fail('\n'.join(msg))
+
     def test_signatures(self):
         if self.tc.layer['type'] == LayerType.SOFTWARE and \
            not self.tc.test_software_layer_signatures: