fix: reject unsupported SKK expressions

map/README

@@ -32,9 +32,9 @@ the normal build image.
 
 `skk2ktrans` accepts one or more EUC-JP SKK files (or standard input), writes
 UTF-8 tab-separated rows, and merges input in command-line and source order.
-It strips annotations, deduplicates candidates, and omits expressions and
-candidates containing whitespace.  Escaped candidate delimiters are rejected;
-rewrite or omit those entries before import.
+It strips annotations, deduplicates candidates, and omits candidates containing
+whitespace.  Rows containing expressions or escaped candidate delimiters are
+rejected; rewrite or omit those rows before import.
 
 `verifymap.py` checks UTF-8, row structure, unique keys, 64-rune keys and
 values, canonical candidate spacing, and duplicate dictionary candidates.

map/skk2ktrans

@@ -34,6 +34,8 @@ function add(k, v, id) {
 		fail("invalid row")
 	if(field ~ /\\/)
 		fail("escaped candidates are unsupported")
+	if(field ~ /\/[([#]/)
+		fail("expression candidates are unsupported")
 	n = split(substr(field, 2, length(field)-2), value, "/")
 	for(i = 1; i <= n; i++)
 		add(key, value[i])