M0: restore page rules after the content stream API change

crates/edit/src/rules.rs

@@ -1,7 +1,7 @@
 //! A page's ruled lines: the horizontal and vertical strokes (and thin filled bars) its content
 //! draws, so exports can tell a ruled table from text that merely lines up (#5149).
 
-use pdfcraft_content::{Matrix, Pieces};
+use pdfcraft_content::Matrix;
 use pdfcraft_cos::Document;
 
 use crate::EditError;
@@ -26,7 +26,7 @@ pub fn page_rules(doc: &Document, page: usize) -> Result<Vec<[f64; 4]>, EditErro
     let pages = pdfcraft_model::pages(doc);
     let p = pages.get(page).ok_or(EditError::NoSuchPage(page))?;
     let streams = crate::text::content_streams(doc, &p.dict)?;
-    let pieces = Pieces::join(&streams.iter().map(|(_, d)| d.as_slice()).collect::<Vec<_>>());
+    let pieces = crate::text::joined(&streams);
     let ops = pieces.parse().ops;
 
     let mut out: Vec<[f64; 4]> = Vec::new();

crates/edit/src/tests.rs

@@ -9501,6 +9501,20 @@ fn page_with(build: impl FnOnce(&mut Document) -> (Object, Dict)) -> Document {
     doc
 }
 
+#[test]
+fn page_rules_join_decoded_streams_before_parsing_operators() {
+    let doc = page_with(|doc| {
+        let first = doc.add(Stream::flate(Dict::new(), b"q 2 0 0 2 0 0 cm 10 20 m 30"));
+        let second = doc.add(Stream::flate(Dict::new(), b"20 l S Q 40 50 1 30 re f"));
+        (Object::Array(vec![Object::Ref(first), Object::Null, Object::Ref(second)]), Dict::new())
+    });
+    assert_eq!(page_rules(&doc, 0).unwrap(), vec![[20.0, 40.0, 60.0, 40.0], [40.0, 50.0, 41.0, 80.0]]);
+    assert_eq!(page_rules(&doc, 1), Err(EditError::NoSuchPage(1)));
+
+    let empty = page_with(|_| (Object::Array(Vec::new()), Dict::new()));
+    assert!(page_rules(&empty, 0).unwrap().is_empty());
+}
+
 #[test]
 fn repeated_content_references_share_one_decode_budget() {
     // One 1 MiB stream (a kilobyte on disk) named 300 times by the page's /Contents.