Fix issue when overriding default chunk splitting rulessam/splitting-fixes-plus-other-stuff

When overriding a default chunk splitting rule, the use 'break' would
mean that some of the other default chunk split rules might be ignored.
This isn't ever what you want.

I also clarified the current behaviour in a comment. I think in future
we should add a mechanism to extend the default rules, as well as the
current mechanism which allows only replacing them. But that is a
separate issue.

1 files changed, 5 insertions, 4 deletions

diff --git a/morphlib/artifactsplitrule.py b/morphlib/artifactsplitrule.py
index 4440f329..76b3fb5e 100644
--- a/morphlib/artifactsplitrule.py
+++ b/morphlib/artifactsplitrule.py
@@ -229,10 +229,11 @@ def unify_chunk_matches(morphology):
     name = morphology['name']
     for suffix, patterns in DEFAULT_CHUNK_RULES:
         ca_name = name + suffix
-        # Default rules are replaced by explicit ones
-        if ca_name in split_rules.artifacts:
-            break
-        split_rules.add(ca_name, FileMatch(patterns))
+        # Explicit rules override the default rules. This is an all-or-nothing
+        # override: there is no way to extend the default split rules right now
+        # without duplicating them in the chunk morphology.
+        if ca_name not in split_rules.artifacts:
+            split_rules.add(ca_name, FileMatch(patterns))
 
     return split_rules