Merge branch 'robustness-and-hackability'

An audit of the shipped program, plus the fixes it found.

The citation parser accepted OCaml integer-literal syntax, so a typo like
'Luke 1_1:5' silently became a different chapter. Four pairs of different
books shared a full title -- 1 and 2 Corinthians both rendered 'Epistola
ad Corinthios' -- leaving 108 citations in 2027 alone that a reader could
not resolve to a book. Spec section 8.5 is now delivered rather than
recorded: shipped styles re-parse their own output. Overlay errors no
longer name OCaml source files at the reader.

Also: the new-overlay scaffold shows citations at the right nesting
level, config --show validates before printing, error messages no longer
echo whole file lines, and a month answers to both spellings of its own
name.

1 files changed, 19 insertions, 0 deletions

diff --git a/test/test_citation.ml b/test/test_citation.ml
index 133553b..dae4610 100644
--- a/test/test_citation.ml
+++ b/test/test_citation.ml
@@ -283,6 +283,11 @@ let parses input expected () =
   | Error e -> Alcotest.failf "%s did not parse: %s" input e
   | Ok t -> Alcotest.(check s) input expected (show t)
 
+let rejects input () =
+  match P.parse input with
+  | Ok t -> Alcotest.failf "%s should not parse, got %s" input (show t)
+  | Error _ -> ()
+
 let test_rejects_unknown_book () =
   Alcotest.(check bool) "error" true (Result.is_error (P.parse "Nonesuch 1:1"))
 
@@ -321,6 +326,20 @@ let parse_suite =
     ("ordinal 3 parses",  `Quick, parses "3 Kings 17:8-16" "kings_3|17:8-16");
     ("ordinal 3 dotted",  `Quick, parses "3 Kgs. 19:3-8" "kings_3|19:3-8");
     ("ordinal 4 parses",  `Quick, parses "4 Kings 5:1-15" "kings_4|5:1-15");
+    (* A citation number must be plain digits and positive. OCaml's
+       [int_of_string] also accepts its own literal syntax, so "1_1" parsed
+       as chapter ELEVEN and "+5" as 5 -- a typo silently becoming a
+       DIFFERENT chapter, which no amount of downstream care can catch.
+       Reachable through a user overlay, which supplies arbitrary strings. *)
+    ("rejects underscore in chapter", `Quick, rejects "Luke 1_1:5");
+    ("rejects underscore in verse",   `Quick, rejects "Luke 1:5_0");
+    ("rejects plus in chapter",       `Quick, rejects "Luke +1:5");
+    ("rejects plus in verse",         `Quick, rejects "Luke 1:+5");
+    ("rejects chapter zero",          `Quick, rejects "Luke 0:5");
+    ("rejects verse zero",            `Quick, rejects "Luke 1:0");
+    (* A descending range is always a transcription error. *)
+    ("rejects descending range",      `Quick, rejects "Luke 1:20-10");
+    ("allows a single-verse range",   `Quick, parses "Luke 1:5-5" "luke|1:5-5");
     ("unknown book",      `Quick, test_rejects_unknown_book);
     ("garbage",           `Quick, test_rejects_garbage) ]