yocto-check-layer: check for duplicate layers when finding layers

detect_layers() is very greedy and if it recurses into poky or bitbake
it will find the test suite layers, such as
bitbake/lib/layerindexlib/tests/testdata/layer4. This is a dummy layer
which claims to be openembedded-layer, so if the real openembedded-layer
is a dependency then layer4 may be used instead, which will cause
errors: initially because it's only compatible with Sumo, but later
because it doesn't contain any recipes.

Add a check that the set of layers we've found doesn't contain any
duplicate collection names with different patterns, and abort if that is
the case as the test will be non-deterministic.

(From OE-Core rev: 0df4bae4ec67d38442620fa08c839528b425e2a8)

Signed-off-by: Ross Burton <ross.burton@arm.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

scripts/yocto-check-layer

@@ -24,7 +24,7 @@ import scriptpath
 scriptpath.add_oe_lib_path()
 scriptpath.add_bitbake_lib_path()
 
-from checklayer import LayerType, detect_layers, add_layers, add_layer_dependencies, get_layer_dependencies, get_signatures, check_bblayers
+from checklayer import LayerType, detect_layers, add_layers, add_layer_dependencies, get_layer_dependencies, get_signatures, check_bblayers, sanity_check_layers
 from oeqa.utils.commands import get_bb_vars
 
 PROGNAME = 'yocto-check-layer'
@@ -119,6 +119,10 @@ def main():
     for l in dep_layers:
         dump_layer_debug(l)
 
+    if not sanity_check_layers(additional_layers + dep_layers, logger):
+        logger.error("Failed layer validation")
+        return 1
+
     logger.info("Detected layers:")
     for layer in layers:
         if layer['type'] == LayerType.ERROR_BSP_DISTRO: