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, 12 insertions, 1 deletions

diff --git a/lib/kernel/overlay_ini.ml b/lib/kernel/overlay_ini.ml
index 6b6249f..09f6d52 100644
--- a/lib/kernel/overlay_ini.ml
+++ b/lib/kernel/overlay_ini.ml
@@ -37,7 +37,18 @@ let parse_sections text =
           end
         else
           match String.index_opt line '=' with
-          | None -> err "line %d: %S is neither a [section] nor a key = value line" n line
+          | None ->
+              (* Echo at most a little of the line. Pointing at line N is
+                 what locates the problem; reproducing the whole line adds
+                 nothing and, when someone has pointed a --lang or --overlay
+                 flag at a file that is not a calendar at all, quietly
+                 copies that file's contents into stderr and any log
+                 collecting it. *)
+              let shown =
+                if String.length line > 40 then String.sub line 0 37 ^ "..."
+                else line
+              in
+              err "line %d: %S is neither a [section] nor a key = value line" n shown
           | Some i ->
               if !cur = None then
                 err "line %d: %S appears before any [section] header" n line