Ensure that the locative is singular-only unless defective

The only case in which the locative form makes sense to be given is for
words which are actually defective and only have a plural
form (e.g. Athēnae). Other than that, it makes no sense to provide
solutions like 'domibus', which have never been attested and are weird
to think about.

As a corollary, the inflection tests have been expanded with the
examples on 'Athēnae' and 'domus', so we ensure the locative behaves as
expected.

Signed-off-by: Miquel Sabaté Solà <mssola@mssola.com>

3 files changed, 19 insertions, 4 deletions

diff --git a/crates/cli/src/inflection.rs b/crates/cli/src/inflection.rs
index b08942f..8799e9b 100644
--- a/crates/cli/src/inflection.rs
+++ b/crates/cli/src/inflection.rs
@@ -191,6 +191,10 @@ mod tests {
             "Rōma | Rōma | Rōmam | Rōmae | Rōmae | Rōmā | Rōmae",
         );
         assert_noun_table(
+            "Athēnae, Athēnārum",
+            "Athēnae | Athēnae | Athēnās | Athēnārum | Athēnīs | Athēnīs | Athēnīs",
+        );
+        assert_noun_table(
             "lupus, lupī",
             "lupus, lupī | lupe, lupī | lupum, lupōs | lupī, lupōrum | lupō, lupīs | lupō, lupīs",
         );
@@ -238,7 +242,10 @@ mod tests {
             "cornū, cornūs",
             "cornū, cornua | cornū, cornua | cornū, cornua | cornūs, cornuum | cornuī, cornibus | cornū, cornibus",
         );
-        // TODO: domus
+        assert_noun_table(
+            "domus, domūs/domī",
+            "domus, domūs | domus, domūs | domum, domūs/domōs | domūs/domī, domuum/domōrum | domuī/domō/domū, domibus | domū/domō, domibus | domī, ",
+        );
         assert_noun_table(
             "diēs, diēī",
             "diēs, diēs | diēs, diēs | diem, diēs | diēī, diērum | diēī, diēbus | diē, diēbus",
diff --git a/lib/mihi/src/lib.rs b/lib/mihi/src/lib.rs
index 11d269a..b6abf2f 100644
--- a/lib/mihi/src/lib.rs
+++ b/lib/mihi/src/lib.rs
@@ -1779,18 +1779,26 @@ pub fn group_declension_inflections(
     let mut table = DeclensionTable::default();
 
     while let Some(row) = it.next().unwrap() {
+        let onlyplural = word.is_flag_set("onlyplural");
+
         // Fetch the number and account for defectives on number.
         let number_i: isize = row.get(1).unwrap();
         let number: usize = usize::try_from(number_i).expect("not expecting a negative number");
-        if (number == 0 && word.is_flag_set("onlyplural"))
-            || (number == 1 && word.is_flag_set("onlysingular"))
-        {
+        if (number == 0 && onlyplural) || (number == 1 && word.is_flag_set("onlysingular")) {
             continue;
         }
 
         let case_i: isize = row.get(3).unwrap();
         let term: String = row.get(4).unwrap();
 
+        // If this is the locative, on the plural, and 'onlyplural' was not
+        // specified, then chances are that the locative in the plural doesn't
+        // exist. That is because it only existed for defective nouns such as
+        // 'Athēnīs'.
+        if case_i == 6 && number == 1 && !onlyplural {
+            continue;
+        }
+
         table.add(
             word,
             usize::try_from(case_i).expect("not expecting a negative number"),
diff --git a/testdata/test.sqlite3 b/testdata/test.sqlite3
index e7733f9..b728b03 100644
--- a/testdata/test.sqlite3
+++ b/testdata/test.sqlite3