.ai import: type with the older TS, Te and TM operators opens

The version 7 and version 3 file format specifications list three text
operators the editing-data reader did not dispatch, so a file whose type
used any of them on a visible layer did not open from its editing data:

- `(text) justified TS` (special characters): the reader adds its
  characters to the story, as it does for `Tx` and `Tj`.
- `Te` (end render) is read and ignored. The reader accepts it with any
  number of operands.
- `TM` (pop text matrix) is read and ignored.

Tests cover each operator in a text object, `TS` without a string and
outside a text object, and `Te` inside a tab definition. The import fuzz
tests add the operators to the legacy type tokens.

crates/engine/tests/import_fuzz.rs

@@ -4053,6 +4053,11 @@ fn arb_ai_token() -> impl Strategy<Value = String> {
             "(\\r) TX",
             "() Tj",
             "(x) Tx",
+            "(\\t) 1 TS",
+            "() /x TS",
+            "Te",
+            "0 0 1e308 -1e308 Te",
+            "TM",
             "7 Tr",
             "-1e308 Ts",
             "1e308 0 Tz",

crates/eps/src/import/ai/read/ops.rs

@@ -356,11 +356,15 @@ impl<'a> Reader<'a> {
             "Tp" => self.begin_text_path(&vals),
             "TP" => self.end_text_path(),
             "TO" => self.end_text(hidden)?,
-            "Tx" | "Tj" | "TX" => self.text_body(w, &vals),
+            // `(text) justified TS`, special characters (§22.6): the reader adds its characters like `Tx`.
+            "Tx" | "Tj" | "TX" | "TS" => self.text_body(w, &vals),
             "Tr" | "Tf" | "Ts" | "Tz" | "Tt" | "TA" | "Tl" | "Ta" | "Ti" | "TC" | "TW" | "Tq" | "Th" => self.text_attr(w, &vals),
             // Attributes the reader doesn't keep (kerning pairs, Far-Eastern type) and final-form
             // positions (§15.3).
             "Tk" | "TK" | "Tc" | "Tw" | "Tm" | "Td" | "T*" | "TR" | "T+" | "T-" | "TV" | "Tv" | "Ty" | "TY" | "TG" | "Tg" | "Tu" | "Xu" => {}
+            // `TM` (pop text matrix) and `Te` (end render), listed in §22.6, keep nothing either; the
+            // reader takes `Te` with any number of operands.
+            "TM" | "Te" => {}
             // The hyphenation language and tab rulers, which the reader doesn't keep either (§22): `XL`,
             // `Xb`/`XB` a tab definition (and the `Xe` tab descriptions between them).
             "XL" | "Xb" | "XB" | "Xe" => {}

crates/eps/src/import/ai/tests.rs

@@ -3001,6 +3001,29 @@ fn legacy_type_attributes_with_bad_operands_stay_as_they_were() {
     assert_eq!(bad.xf, good.xf);
 }
 
+/// `(text) justified TS` (special characters, §22.6) adds its characters to the story like `Tx`
+/// and `Tj`, whichever its flag. Without a string, or outside a text object, it adds nothing.
+#[test]
+fn legacy_special_characters_join_the_story() {
+    let texts = legacy_texts(&point_type("", "One").replace("TO\n", "(\\t) 0 TS\n(Two\\r) 1 TS\n(Three) Tx\nTO\n"));
+    let [t] = texts.as_slice() else { panic!("{texts:?}") };
+    assert_eq!(t.plain_text(), "One\tTwo\nThree");
+    let texts = legacy_texts(&format!("(x) 0 TS\n{}", point_type("0 TS", "Hi")));
+    let [t] = texts.as_slice() else { panic!("{texts:?}") };
+    assert_eq!(t.plain_text(), "Hi");
+}
+
+/// `Te` (end render, §22.6) reads in a text object with no operands and with four, inside a tab
+/// definition too, and keeps nothing; so does `TM` (pop text matrix, §22.6).
+#[test]
+fn legacy_end_render_and_text_matrix_pop_read() {
+    for te in ["Te", "0 0 1 36 Te", "36 0 Xb\n0 0 1 36 Te\nXB", "1 0 0 1 10 50 Tm\nTM"] {
+        let texts = legacy_texts(&point_type(te, "Hi"));
+        let [t] = texts.as_slice() else { panic!("{te}: {texts:?}") };
+        assert_eq!(t.plain_text(), "Hi", "{te}");
+    }
+}
+
 /// Spacing is kept to the ranges the Justification options take, a Minimum, Desired and Maximum
 /// out of order go back to their defaults, and hyphenation's letter counts and limit to the ranges
 /// `text.setFormat` takes.

docs/file-format-parity.md

@@ -122,7 +122,8 @@ private editing data. VectorCraft:
   without the prolog opens since #1027, its legacy type (`To` … `TO`) since #868. Graphs (`%_Gs` … `%_GS`)
   come in as their drawn art, as plain groups, paths and type, without their data or settings, with a note.
   without the prolog opens since #1027, its legacy type (`To` … `TO`) since #868, with its paragraphs' letter
-  and word spacing (`TC`, `TW`), hanging punctuation (`Tq`) and hyphenation (`Th`). Its patterns in
+  and word spacing (`TC`, `TW`), hanging punctuation (`Tq`) and hyphenation (`Th`); its special characters
+  (`TS`) join the story, and end render (`Te`) and pop text matrix (`TM`) are read and ignored. Its patterns in
   the version 7 form (a list of `@` and `&` layers, `_ &` for the tile's background) open as pattern swatches,
   with a fill's offset, scale, rotation, reflection and shear applied before its matrix.
   Its area type with several linked areas opens as threaded frames, one for each area with its own matrix,