.ai import: type on a path keeps its effect, alignment and flip

Type on a path from a file's text document opened as Rainbow on its
baseline, not flipped, whatever Type on a Path Options the frame kept.
Each frame now keeps its effect (Rainbow, Skew, 3D Ribbon, Stair Step,
Gravity), Align to Path (Ascender, Descender, Center, Baseline) and Flip.
A code or flag that can't be read leaves that option at its default.

Flipped type opens with the frame's path reversed once, after a copied
object takes its own art path, and an open path's end bracket stays so
the type starts where the file's range ends.

Spacing is still fitted from the file's layout. The fit now measures along
the path when Align to Path moves the baselines off it, and it follows the
glyphs' feet under 3D Ribbon, whose baselines stay level.

crates/engine/tests/import_fuzz.rs

@@ -3043,6 +3043,36 @@ fn arb_area_options() -> impl Strategy<Value = String> {
     prop::collection::vec((keys, values), 0..8).prop_map(|kv| kv.iter().map(|(k, v)| format!("/{k} {v}")).collect::<Vec<_>>().join(" "))
 }
 
+/// Type on a Path Options as a frame might keep them at key 11: nothing, a value that isn't a
+/// dictionary, or a dictionary of codes and flags of any value or type.
+fn arb_path_options() -> impl Strategy<Value = String> {
+    let keys = prop::sample::select(vec!["0", "1", "2", "3", "4", "6", "7", "18", "22"]);
+    let values = prop::sample::select(vec![
+        "0",
+        "1",
+        "2",
+        "3",
+        "4",
+        "5",
+        "-1",
+        "2.5",
+        "1e400",
+        "NaN",
+        "inf",
+        "(x)",
+        "true",
+        "false",
+        "/Name",
+        "[ 1 ]",
+        "<< /0 1 >>",
+    ]);
+    (prop::collection::vec((keys, values), 0..6), 0usize..3).prop_map(|(kv, shape)| match shape {
+        0 => format!("/11 << {} >>", kv.iter().map(|(k, v)| format!("/{k} {v}")).collect::<Vec<_>>().join(" ")),
+        1 => "/11 3".to_string(),
+        _ => String::new(),
+    })
+}
+
 /// A text document of `kinds.len()` stories, story `i` in frame `i` of kind `kinds[i]` (0 point type,
 /// 1 area type, 2 type on a path, others a kind the reader doesn't know), with a line break inside
 /// its paragraph (`\x03`) at each of `soft` (by character, wrapping, the story's end included) and
@@ -3192,6 +3222,18 @@ proptest! {
         survive(".ai text frames with hostile area options", || Some(vectorcraft_eps::layered_ai(&private, Document::new(100.0, 100.0), vec![], false, false, 1.0).0))?;
     }
 
+    /// The type on a path of the same text document with hostile Type on a Path Options, opened as
+    /// an EPS document and as a `.ai`'s editing data.
+    #[test]
+    fn text_frames_with_hostile_path_options_never_panic(options in arb_path_options()) {
+        let text = frames_document_text().replacen("/6 [ 0.5 2.0 ]", &format!("/6 [ 0.5 2.0 ] {options}"), 1);
+        let editing = text_editing_of(&text, FRAME_OBJECTS);
+        let bytes = editing_eps(&editing);
+        survive("EPS text frames with hostile path options", || vectorcraft_engine::cmd::fileio::load("x.eps", &bytes).ok().map(|l| l.doc))?;
+        let private = [b"%AI24_ZStandard_Data".as_slice(), &zstd(&editing)].concat();
+        survive(".ai text frames with hostile path options", || Some(vectorcraft_eps::layered_ai(&private, Document::new(100.0, 100.0), vec![], false, false, 1.0).0))?;
+    }
+
     /// The same for vertical type and Tate-chu-yoko runs: orientations and baseline directions of
     /// any value, type or size.
     #[test]