rust-matchers: better support file_set in IntersectionMatcher
Previously, if both of the input matchers had non-exact file sets,
IntersectionMatcher would simply have an empty fileset.
Now, we duplicate Python behavior: we *union* the filesets of the
matchers in that case. This makes some sense, because without exact
input file sets, we can't do an exact intersection and must
over-approximate.
Concretely, this is necessary because the file_set is the list of
files that were explicitly listed by the user, and we want to provide
explicit errors for all such files, from both matchers.
--- a/rust/hg-core/src/matchers.rs Mon Aug 21 10:00:08 2023 +0200
+++ b/rust/hg-core/src/matchers.rs Wed Aug 02 09:57:29 2023 -0400
@@ -479,7 +479,13 @@
m1_files.iter().cloned().filter(|f| m2.matches(f)).collect()
})
} else {
- None
+ // without exact input file sets, we can't do an exact
+ // intersection, so we must over-approximate by
+ // unioning instead
+ m1.file_set().map(|m1_files| match m2.file_set() {
+ Some(m2_files) => m1_files.union(m2_files).cloned().collect(),
+ None => m1_files.iter().cloned().collect(),
+ })
};
Self { m1, m2, files }
}