From 392406eb4ad488bddacb9eae12ad73b987e13a30 Mon Sep 17 00:00:00 2001
From: skylar taylor-barrick <hi@skylar.cc>
Date: Sat, 17 Oct 2026 21:50:58 +0200
Subject: [PATCH 1/3] fix(content): read a comment at the end of a content
 stream as the renderer does (#3081)

Pieces::join separated a page's content streams with a newline, which ended
a comment left open at the end of one stream. hayro, MuPDF and Poppler join
them with a space, so the comment runs on into the next stream and hides its
first line. Edit text, object_list, the redaction audit, redaction and the
Office/HTML export therefore saw text and boxes that nothing draws, and
redacting unrelated text on the page made the hidden content visible: the
rewritten stream dropped the comment.

- Pieces::join uses a space, so every reader of the joined streams agrees
  with rendering.
- The parser records, per piece, whether a top-level comment runs into it
  and out of it (boundaries only, not every comment). A redaction rewrite
  of a piece ends an incoming comment before its first operator and leaves
  an outgoing one open, so hidden content stays hidden.
- Reading for export parses the streams joined, instead of one by one.
- The redaction tag check compares the joined streams the same way.
- Pieces::piece_of uses a binary search.
---
 crates/audit/src/tests.rs   |  19 +++++++
 crates/content/src/lib.rs   |  72 +++++++++++++++++++++++--
 crates/content/src/tests.rs | 105 ++++++++++++++++++++++++++++++++++++
 crates/edit/src/text.rs     |  14 ++++-
 crates/redact/src/interp.rs |  16 +++++-
 crates/redact/src/lib.rs    |   3 +-
 crates/redact/src/tests.rs  |  39 ++++++++++++++
 7 files changed, 258 insertions(+), 10 deletions(-)

diff --git a/crates/audit/src/tests.rs b/crates/audit/src/tests.rs
index ed36a8d5e..64ea05bde 100644
--- a/crates/audit/src/tests.rs
+++ b/crates/audit/src/tests.rs
@@ -500,3 +500,22 @@ fn forms_nested_past_depth_limit_fail_closed() {
     let result = audit_redactions(&open(nested_forms(33)));
     assert!(matches!(result, Err(crate::AuditError::TooDeep)), "{result:?}");
 }
+
+#[test]
+fn comment_across_streams_neither_invents_text_nor_a_cover() {
+    let doc = open(two_streams(b"BT /F1 24 Tf 72 700 Td (Visible text) Tj ET % note", b"0 g 70 690 200 40 re f"));
+    assert!(audit_redactions(&doc).unwrap().is_empty(), "commented cover must not be reported");
+    let doc = open(two_streams(b"BT /F1 24 Tf 72 700 Td (Before comment) Tj ET % note", b"BT /F1 24 Tf 72 650 Td (After comment) Tj ET"));
+    let text: String = pdfcraft_edit::text_lines(&doc, 0).unwrap().into_iter().map(|line| line.text).collect();
+    assert!(!text.contains("After comment"), "editor exposed phantom text: {text}");
+}
+
+#[test]
+fn reading_blocks_respect_stream_comments_and_split_operands() {
+    let doc = open(two_streams(b"BT /F1 24 Tf 72 700 Td (Before comment) Tj ET % note", b"BT /F1 24 Tf 72 650 Td (After comment) Tj ET"));
+    let text: String = pdfcraft_edit::reading_blocks(&doc, 0).unwrap().into_iter().map(|block| block.editor_text).collect();
+    assert_eq!(text, "Before comment");
+    let doc = open(two_streams(b"BT /F1 24 Tf 72 700 Td (Split operand)", b"Tj ET"));
+    let text: String = pdfcraft_edit::reading_blocks(&doc, 0).unwrap().into_iter().map(|block| block.editor_text).collect();
+    assert_eq!(text, "Split operand");
+}
diff --git a/crates/content/src/lib.rs b/crates/content/src/lib.rs
index 32334e047..c7c8bca9e 100644
--- a/crates/content/src/lib.rs
+++ b/crates/content/src/lib.rs
@@ -60,6 +60,10 @@ pub struct Parsed {
     pub ops: Vec<Op>,
     /// Bytes that could not be read as operands or operators.
     pub skipped: usize,
+    /// For [`Pieces::parse`]: per piece, whether a comment runs into it from the piece before
+    /// and whether one runs out of it into the next. Only boundaries are recorded, so the size
+    /// depends on the number of pieces, not of comments.
+    comment_edges: Vec<(bool, bool)>,
 }
 
 fn is_ws(b: u8) -> bool {
@@ -72,12 +76,25 @@ fn is_delim(b: u8) -> bool {
 
 /// Parse a (decoded) content stream.
 pub fn parse(data: &[u8]) -> Parsed {
-    let mut out = Parsed::default();
+    parse_pieces(data, &[])
+}
+
+/// Parse `data`, recording which of the piece boundaries `ends` (as in [`Pieces`]) a comment
+/// crosses.
+fn parse_pieces(data: &[u8], ends: &[usize]) -> Parsed {
+    let mut out = Parsed { comment_edges: vec![(false, false); ends.len()], ..Parsed::default() };
+    let mut boundary = 0;
     let mut lx = Lexer::new(data, 0);
     let mut operands: Vec<Object> = Vec::new();
     let mut start: Option<usize> = None;
     loop {
+        let trivia = lx.pos;
         lx.skip_ws();
+        // Only the whitespace the lexer skips here holds top-level comments: a `%` inside a
+        // string, a name, an array or dictionary operand or inline image data is not one.
+        if boundary < ends.len() {
+            comment_edges(data, trivia..lx.pos, ends, &mut boundary, &mut out.comment_edges);
+        }
         let Some(&b) = data.get(lx.pos) else { break };
         let at = lx.pos;
         let operand_start = matches!(b, b'/' | b'(' | b'<' | b'[' | b'+' | b'-' | b'.') || b.is_ascii_digit();
@@ -148,6 +165,39 @@ pub fn parse(data: &[u8]) -> Parsed {
     out
 }
 
+/// Record the piece boundaries crossed by the comments in `trivia` (skipped whitespace and
+/// comments). `boundary` is the first boundary not yet passed; boundaries only move forward.
+fn comment_edges(data: &[u8], trivia: std::ops::Range<usize>, ends: &[usize], boundary: &mut usize, edges: &mut [(bool, bool)]) {
+    let mut at = trivia.start;
+    while at < trivia.end {
+        if data.get(at) != Some(&b'%') {
+            at += 1;
+            continue;
+        }
+        let comment = at;
+        while at < trivia.end && !matches!(data.get(at), Some(b'\r' | b'\n')) {
+            at += 1;
+        }
+        // The separator of piece `boundary` is the last byte before its end.
+        while let Some(&end) = ends.get(*boundary) {
+            let separator = end.saturating_sub(1);
+            if separator >= at {
+                break;
+            }
+            if separator >= comment {
+                if let Some(edge) = edges.get_mut(*boundary) {
+                    edge.1 = true;
+                }
+                // Includes a comment whose end of line is the next piece's first byte.
+                if let Some(edge) = edges.get_mut(boundary.saturating_add(1)) {
+                    edge.0 = true;
+                }
+            }
+            *boundary += 1;
+        }
+    }
+}
+
 /// Read an inline image starting after `BI`: (parameters, data, position after `EI`). `Err` holds
 /// the position after the `EI` (or the end of the stream) of an image whose parameters can't be read.
 fn inline_image(data: &[u8], pos: usize) -> Result<(Dict, Vec<u8>, usize), usize> {
@@ -305,7 +355,9 @@ pub fn serialize_ops(ops: &[Op]) -> Vec<u8> {
 /// A page's content streams joined into the one stream they are. Writers may split it between
 /// any two tokens (ISO 32000-2 §7.8.2), so an operator's operands can end one piece and its
 /// keyword start the next: parse the pieces joined ([`Pieces::parse`]) and map positions back
-/// with [`Pieces::piece_of`]. A newline separates the pieces so tokens never run together.
+/// with [`Pieces::piece_of`]. A space separates the pieces, as renderers join them (hayro,
+/// MuPDF and Poppler alike): tokens never run together, and a comment at the end of a piece
+/// runs on into the next one, up to its first end of line.
 #[derive(Clone, Debug, Default, PartialEq)]
 pub struct Pieces {
     data: Vec<u8>,
@@ -319,7 +371,7 @@ impl Pieces {
         let mut ends = Vec::with_capacity(pieces.len());
         for p in pieces {
             data.extend_from_slice(p.as_ref());
-            data.push(b'\n');
+            data.push(b' ');
             ends.push(data.len());
         }
         Pieces { data, ends }
@@ -341,12 +393,22 @@ impl Pieces {
 
     /// Parse the pieces as one stream.
     pub fn parse(&self) -> Parsed {
-        parse(&self.data)
+        parse_pieces(&self.data, &self.ends)
+    }
+
+    /// Per piece, from `parsed` (this piece set's [`Pieces::parse`]): whether a comment runs
+    /// into it from the piece before, and whether one runs out of it into the next. A writer
+    /// that rewrites a piece without its comments must keep both: end the incoming comment
+    /// before its first operator, and leave a comment open at its end.
+    pub fn comment_edges(&self, parsed: &Parsed) -> Vec<(bool, bool)> {
+        let mut edges = parsed.comment_edges.clone();
+        edges.resize(self.len(), (false, false));
+        edges
     }
 
     /// The piece holding joined position `at` (the last piece for positions past the end).
     pub fn piece_of(&self, at: usize) -> usize {
-        self.ends.iter().position(|&e| at < e).unwrap_or(self.ends.len().saturating_sub(1))
+        self.ends.partition_point(|&e| e <= at).min(self.ends.len().saturating_sub(1))
     }
 
     /// The pieces an operator spans: (the one its first token is in, the one its keyword is in).
diff --git a/crates/content/src/tests.rs b/crates/content/src/tests.rs
index 18e0b8cbc..1119bdaf9 100644
--- a/crates/content/src/tests.rs
+++ b/crates/content/src/tests.rs
@@ -283,3 +283,108 @@ fn pieces_parse_as_one_stream_and_splice_back() {
     assert_eq!(out.len(), 3);
     assert!(Pieces::join::<&[u8]>(&[]).splice([(0..1, b"x".to_vec())]).is_empty());
 }
+
+#[test]
+fn stream_boundary_comment_matches_space_concatenation() {
+    for eol in [b"\n".as_slice(), b"\r", b"\r\n"] {
+        let mut tail = b"(HIDDEN) Tj".to_vec();
+        tail.extend(eol);
+        tail.extend(b"(LIVE) Tj");
+        let pieces = Pieces::join(&[b"BT % comment".as_slice(), b"(ALSO HIDDEN) Tj", &tail, b"ET"]);
+        let parsed = pieces.parse();
+        let shown: Vec<_> = parsed.ops.iter().filter(|op| op.is("Tj")).collect();
+        assert_eq!(shown.len(), 1);
+        assert_eq!(shown[0].operands[0].as_string().unwrap().bytes, b"LIVE");
+    }
+}
+
+#[test]
+fn comment_edges_terminate_at_next_piece_byte_zero() {
+    for eol in [b"\n".as_slice(), b"\r", b"\r\n"] {
+        let mut next = eol.to_vec();
+        next.extend_from_slice(b"q Q");
+        let pieces = Pieces::join(&[b"% outgoing".as_slice(), next.as_slice()]);
+        let parsed = pieces.parse();
+        assert_eq!(pieces.comment_edges(&parsed), vec![(false, true), (true, false)], "EOL {eol:?}");
+        assert_eq!(parsed.ops.iter().map(|op| op.op.as_slice()).collect::<Vec<_>>(), vec![b"q".as_slice(), b"Q"]);
+    }
+}
+
+#[test]
+fn comment_edges_span_empty_pieces_and_end_of_content() {
+    let pieces = Pieces::join(&[b"q % outgoing".as_slice(), b"", b"", b"ignored\nQ"]);
+    let parsed = pieces.parse();
+    assert_eq!(pieces.comment_edges(&parsed), vec![(false, true), (true, true), (true, true), (true, false)]);
+    assert_eq!(parsed.ops.iter().map(|op| op.op.as_slice()).collect::<Vec<_>>(), vec![b"q".as_slice(), b"Q"]);
+
+    let pieces = Pieces::join(&[b"% outgoing".as_slice(), b"", b"still ignored"]);
+    let parsed = pieces.parse();
+    assert_eq!(pieces.comment_edges(&parsed), vec![(false, true), (true, true), (true, true)]);
+    assert!(parsed.ops.is_empty());
+
+    let pieces = Pieces::join::<&[u8]>(&[]);
+    assert!(pieces.comment_edges(&pieces.parse()).is_empty());
+}
+
+#[test]
+fn comment_edges_ignore_percent_inside_operands_and_image_data() {
+    for first in [
+        b"(literal % not a comment) Tj".as_slice(),
+        b"/Percent#25Name MP",
+        b"[(literal % not a comment)] TJ",
+        b"/P << /ActualText (literal % not a comment) >> BDC EMC",
+        b"BI /W 1 /H 1 /BPC 8 /CS /G ID % EI",
+    ] {
+        let pieces = Pieces::join(&[first, b"q Q"]);
+        let parsed = pieces.parse();
+        assert_eq!(pieces.comment_edges(&parsed), vec![(false, false), (false, false)], "{first:?}");
+        assert_eq!(parsed.ops.last().unwrap().op, b"Q");
+        assert_eq!(parsed.skipped, 0);
+    }
+}
+
+#[test]
+fn compound_operand_comment_split_is_owned_by_spanning_operator() {
+    for parts in [[b"[(A) % ignored".as_slice(), b"still ignored\n(B)] TJ"], [b"/P << /MCID 0 % ignored".as_slice(), b"still ignored\n>> BDC"]] {
+        let pieces = Pieces::join(&parts);
+        let parsed = pieces.parse();
+        // The object lexer consumes this nested comment. Its containing operator spans
+        // both pieces, which forces both to be rewritten together by the redactor.
+        assert_eq!(pieces.comment_edges(&parsed), vec![(false, false), (false, false)]);
+        assert_eq!(parsed.ops.len(), 1);
+        assert_eq!(pieces.pieces_of(&parsed.ops[0]), (0, 1));
+        assert_eq!(parsed.skipped, 0);
+    }
+}
+
+#[test]
+fn comment_edges_do_not_confuse_local_comments_with_boundary_comments() {
+    let pieces = Pieces::join(&[b"% local\nq % crossing".as_slice(), b"ignored\n% local again\nQ\n% final local\n", b"q Q"]);
+    let parsed = pieces.parse();
+    assert_eq!(pieces.comment_edges(&parsed), vec![(false, true), (true, false), (false, false)]);
+    assert_eq!(parsed.ops.iter().map(|op| op.op.as_slice()).collect::<Vec<_>>(), vec![b"q".as_slice(), b"Q", b"q", b"Q"]);
+}
+
+#[test]
+fn comment_edge_storage_depends_on_piece_count_not_comment_count() {
+    let mut first = b"%\n".repeat(16_384);
+    first.extend_from_slice(b"q % crossing");
+    let pieces = Pieces::join(&[first.as_slice(), b"ignored\nQ"]);
+    let parsed = pieces.parse();
+    assert_eq!(pieces.comment_edges(&parsed), vec![(false, true), (true, false)]);
+    assert_eq!(parsed.ops.len(), 2);
+    // Also exercise public parsing without piece-boundary metadata.
+    assert_eq!(parse(&first).ops.len(), 1);
+}
+
+#[test]
+fn piece_lookup_preserves_exact_boundary_and_empty_piece_mapping() {
+    // Joined layout: q<space><space>Q<space>; separator belongs to prior piece.
+    let pieces = Pieces::join(&[b"q".as_slice(), b"", b"Q"]);
+    for (at, expected) in [(0, 0), (1, 0), (2, 1), (3, 2), (4, 2), (5, 2), (usize::MAX, 2)] {
+        assert_eq!(pieces.piece_of(at), expected, "position {at}");
+    }
+    let empty = Pieces::join::<&[u8]>(&[]);
+    assert_eq!(empty.piece_of(0), 0);
+    assert_eq!(empty.piece_of(usize::MAX), 0);
+}
diff --git a/crates/edit/src/text.rs b/crates/edit/src/text.rs
index 9c83cf9a3..93d1b54fc 100644
--- a/crates/edit/src/text.rs
+++ b/crates/edit/src/text.rs
@@ -1276,8 +1276,18 @@ fn reading_lines(doc: &Document, page: usize) -> Result<Vec<TextLine>, EditError
     let streams = content_streams(doc, &p.dict);
     let mut w = Walk { doc, lines: Vec::new(), next_stream: streams.len(), path: Vec::new(), visits: 0 };
     let mut carry = Carry::new();
-    for (si, (_, data)) in streams.into_iter().enumerate() {
-        walk(&mut w, &parse(&data).ops, &res, &mut carry, si);
+    // Read the page's streams as the one stream they are, as rendering and editing do: a
+    // comment or an operator's operands can run on from one stream into the next. Each operator
+    // still counts as its first stream's, which keeps lines from different streams apart.
+    let pieces = Pieces::join(&streams.into_iter().map(|(_, data)| data).collect::<Vec<_>>());
+    let mut grouped: Vec<Vec<Op>> = (0..pieces.len()).map(|_| Vec::new()).collect();
+    for op in pieces.parse().ops {
+        if let Some(group) = grouped.get_mut(pieces.pieces_of(&op).0) {
+            group.push(op);
+        }
+    }
+    for (si, ops) in grouped.iter().enumerate() {
+        walk(&mut w, ops, &res, &mut carry, si);
     }
     let mut lines = w.lines;
     // A visual-order Indic font draws pre-base vowel signs before their consonant.
diff --git a/crates/redact/src/interp.rs b/crates/redact/src/interp.rs
index c76e11995..50802eff3 100644
--- a/crates/redact/src/interp.rs
+++ b/crates/redact/src/interp.rs
@@ -380,6 +380,9 @@ pub(crate) fn process(doc: &mut Document, scope: &mut Scope<'_>, streams: &[Vec<
     // next. Parse them joined, then give each operator back to the piece its keyword is in.
     let joined = Pieces::join(streams);
     let mut parsed = joined.parse();
+    // A rewritten piece loses its comments, so keep where they began and ended: a comment that
+    // ran on into the next piece still hides that piece's first line.
+    let comment_edges = joined.comment_edges(&parsed);
     if !scope.hidden_layers.is_empty() {
         let props = res_dict(doc, resources, b"Properties");
         let (kept, removed) = strip_hidden_layers(doc, scope, parsed.ops, &props);
@@ -405,7 +408,7 @@ pub(crate) fn process(doc: &mut Document, scope: &mut Scope<'_>, streams: &[Vec<
         }
     }
 
-    for (piece, mut changed) in pieces.into_iter().zip(rewrite) {
+    for ((piece, mut changed), (comment_in, comment_out)) in pieces.into_iter().zip(rewrite).zip(comment_edges) {
         let mut ops: Vec<Op> = Vec::with_capacity(piece.len());
         for op in piece {
             let o = op.op.as_slice();
@@ -622,7 +625,16 @@ pub(crate) fn process(doc: &mut Document, scope: &mut Scope<'_>, streams: &[Vec<
         if !path.is_empty() {
             ops.append(&mut path);
         }
-        out.streams.push(changed.then(|| serialize_ops(&ops)));
+        out.streams.push(changed.then(|| {
+            // The piece before still ends inside a comment: end it before the first operator.
+            let mut bytes = if comment_in { b"\n".to_vec() } else { Vec::new() };
+            bytes.extend(serialize_ops(&ops));
+            // The piece ended inside a comment that hid the start of the next one: keep it open.
+            if comment_out {
+                bytes.push(b'%');
+            }
+            bytes
+        }));
     }
     out
 }
diff --git a/crates/redact/src/lib.rs b/crates/redact/src/lib.rs
index 61231bd98..21af3691c 100644
--- a/crates/redact/src/lib.rs
+++ b/crates/redact/src/lib.rs
@@ -400,7 +400,8 @@ pub fn apply(doc: &mut Document, pages: Option<&[usize]>) -> Result<Report, Reda
             // Tags must not keep what the page no longer shows.
             let after = doc.get(page.obj).as_dict().cloned().unwrap_or_default();
             let (_, new_data) = page_streams(doc, &after, pi)?;
-            let (changed_ids, empty_ids) = tags::touched(doc, &resources, &data.join(&b'\n'), &new_data.join(&b'\n'));
+            let (changed_ids, empty_ids) =
+                tags::touched(doc, &resources, pdfcraft_content::Pieces::join(&data).data(), pdfcraft_content::Pieces::join(&new_data).data());
             report.tags += tags::clean(doc, page.obj, None, &changed_ids, &empty_ids)?;
         }
 
diff --git a/crates/redact/src/tests.rs b/crates/redact/src/tests.rs
index b9a230fc4..89feab42a 100644
--- a/crates/redact/src/tests.rs
+++ b/crates/redact/src/tests.rs
@@ -1117,3 +1117,42 @@ fn masks_and_alternates_outside_redaction_stay() {
     assert!(image.dict.contains(b"SMask") && image.dict.contains(b"Alternates"));
     assert_eq!(image.decoded().unwrap(), b"PUBLIC_TOPBOTTOM");
 }
+
+#[test]
+fn stream_boundary_comment_stays_inert_after_unrelated_redaction() {
+    for tail in [b"BT /F1 10 Tf 10 200 Td (HIDDEN) Tj ET".as_slice(), b"BT /F1 10 Tf 10 200 Td (HIDDEN) Tj ET\nBT /F1 10 Tf 10 250 Td (LIVE) Tj ET"] {
+        let mut doc = one_page(b"BT /F1 10 Tf 10 100 Td (REMOVE) Tj ET % note", "", vec![]);
+        let hidden = doc.add(Object::Stream(Stream::from_raw(Dict::new(), tail.to_vec())));
+        let page = pdfcraft_model::pages(&doc)[0].obj;
+        doc.update_dict(page, |d| d.set(b"Contents".to_vec(), Object::Array(vec![Object::Ref(ObjRef::new(4, 0)), Object::Ref(hidden)]))).unwrap();
+        mark(&mut doc, 0, &[[9.0, 95.0, 50.0, 110.0]], "");
+        assert_eq!(apply(&mut doc, None).unwrap().glyphs, 6);
+        let reopened = reopen(&doc);
+        let page = &pdfcraft_model::pages(&reopened)[0];
+        let (_, data) = page_streams(&reopened, &page.dict, 0).unwrap();
+        // Independent of Pieces::join: the renderer concatenates streams with spaces.
+        let ops = pdfcraft_content::parse(&data.join(&b' ')).ops;
+        assert!(!ops.iter().any(|o| o.operands.iter().any(|v| v.as_string().is_some_and(|s| s.bytes == b"HIDDEN"))), "hidden text became executable");
+        let live = ops.iter().any(|o| o.operands.iter().any(|v| v.as_string().is_some_and(|s| s.bytes == b"LIVE")));
+        assert_eq!(live, tail.contains(&b'\n'));
+    }
+}
+
+#[test]
+fn rewriting_a_piece_keeps_its_leading_comment_terminator() {
+    for eol in [b"\n".as_slice(), b"\r", b"\r\n"] {
+        let mut doc = one_page(b"q Q % note", "", vec![]);
+        let mut tail = eol.to_vec();
+        tail.extend(b"BT /F1 10 Tf 10 100 Td (REMOVE) Tj ET BT /F1 10 Tf 10 200 Td (KEEP) Tj ET");
+        let second = doc.add(Object::Stream(Stream::from_raw(Dict::new(), tail)));
+        let page = pdfcraft_model::pages(&doc)[0].obj;
+        doc.update_dict(page, |d| d.set(b"Contents".to_vec(), Object::Array(vec![Object::Ref(ObjRef::new(4, 0)), Object::Ref(second)]))).unwrap();
+        mark(&mut doc, 0, &[[9.0, 95.0, 50.0, 110.0]], "");
+        assert_eq!(apply(&mut doc, None).unwrap().glyphs, 6);
+        let p = &pdfcraft_model::pages(&doc)[0];
+        let (_, data) = page_streams(&doc, &p.dict, 0).unwrap();
+        let ops = pdfcraft_content::parse(&data.join(&b' ')).ops;
+        assert_eq!(ops.iter().filter(|o| o.is("BT")).count(), 2, "leading EOL lost; first live operator swallowed");
+        assert!(ops.iter().any(|o| o.operands.iter().any(|v| v.as_string().is_some_and(|s| s.bytes == b"KEEP"))));
+    }
+}

From 43bb98eb88d111875ebdc18fc7722c377580be52 Mon Sep 17 00:00:00 2001
From: skylar taylor-barrick <hi@skylar.cc>
Date: Sat, 17 Oct 2026 21:50:58 +0200
Subject: [PATCH 2/3] fix(edit): isolate new marks from state left by content
 after an earlier wrapper (#3084)

place_tagged wrapped the page's content in q/Q only when no Wrap stream
existed yet. Content appended after an earlier wrapper (by another tool, or
an older OCR layer) that left a cm, a clip or text state set then moved,
hid or distorted every later header, Bates number, watermark, added text,
flattened annotation and redaction cover.

Placing a mark on top now reads the page's actual operators instead of the
/PCMark tags. When the content parses cleanly with balanced q/Q and closed
text objects and paths, the stretch from the first stream that leaves state
set is wrapped, once, at a stream boundary no comment runs into. Content
that is already self-contained gets no new wrapper, so repeated marks don't
pile up.

Content that can't be read that precisely (stray bytes, unbalanced q/Q, an
unfinished text object or path, too large) is wrapped whole as before,
rather than refusing: redaction stamps its covers after removing the text
and can't back out. A q that content leaves open is closed after it, where
closing it changes nothing already drawn.

The wrapper's close now starts with a newline, so a comment at the end of
the content before it can't swallow the Q. Removing marks strips only
wrapper pairs that end the list, keeping one that later content still
relies on, and recognises the older close bytes too.
---
 crates/edit/src/lib.rs   | 205 ++++++++++++++++++++++++++++++++---
 crates/edit/src/tests.rs | 226 ++++++++++++++++++++++++++++++++++++++-
 2 files changed, 413 insertions(+), 18 deletions(-)

diff --git a/crates/edit/src/lib.rs b/crates/edit/src/lib.rs
index 515f17d8d..cef8f3c9d 100644
--- a/crates/edit/src/lib.rs
+++ b/crates/edit/src/lib.rs
@@ -327,7 +327,37 @@ fn add_resources(doc: &mut Document, page: &pdfcraft_model::Page, opacity: Optio
 }
 
 const WRAP_OPEN: &[u8] = b"q %PdfCraft\n";
-const WRAP_CLOSE: &[u8] = b"Q %PdfCraft\n";
+/// Starts with an end of line, so a comment left open at the end of the content before it
+/// can't swallow the `Q`. Older files have the close without it.
+const WRAP_CLOSE: &[u8] = b"\nQ %PdfCraft\n";
+const OLD_WRAP_CLOSE: &[u8] = b"Q %PdfCraft\n";
+
+/// Whether `bytes` are a wrapper's close: [`WRAP_CLOSE`] after a `Q` for each `q` the wrapped
+/// content left open, or [`OLD_WRAP_CLOSE`].
+fn is_wrap_close(bytes: &[u8]) -> bool {
+    let mut rest = bytes;
+    loop {
+        if rest == WRAP_CLOSE || rest == OLD_WRAP_CLOSE {
+            return true;
+        }
+        match rest.strip_prefix(b"\nQ".as_slice()) {
+            Some(shorter) => rest = shorter,
+            None => return false,
+        }
+    }
+}
+
+/// A `Wrap`-tagged stream's role from its exact bytes: `Some(true)` for an open, `Some(false)`
+/// for a close.
+fn wrapper_role(doc: &Document, o: &Object) -> Option<bool> {
+    if stream_tag(doc, o).as_deref() != Some("Wrap") {
+        return None;
+    }
+    let Object::Stream(stream) = &*doc.resolve(o) else { return None };
+    // Wrappers are a few bytes; one that decodes to more isn't PdfCraft's.
+    let bytes = stream.decoded_within(64 * 1024).ok()?;
+    if bytes == WRAP_OPEN { Some(true) } else { is_wrap_close(&bytes).then_some(false) }
+}
 
 #[cfg(test)]
 fn stream_bytes(doc: &Document, o: &Object) -> Option<Vec<u8>> {
@@ -350,27 +380,138 @@ fn tagged(tag: &str) -> Dict {
     d
 }
 
+/// What placing a mark on top needs, from the page's actual operators (not the `/PCMark` tags,
+/// which another writer may keep, copy or forge).
+enum Isolation {
+    /// The content parses cleanly with balanced `q`/`Q` and closed text objects and paths.
+    /// `suffix`: the stream from which the content leaves graphics state set (or a comment open)
+    /// that a mark on top must not inherit, so it needs a wrapper from there to the end.
+    /// `wrappers`: PdfCraft wrapper pairs (open, close) as stream indexes.
+    Clean { suffix: Option<usize>, wrappers: Vec<(usize, usize)> },
+    /// The content could not be read that precisely (it doesn't decode, is too large, or has
+    /// stray bytes, unbalanced `q`/`Q` or an unfinished text object or path). `unclosed` is
+    /// the count of `q` left open at the end, when known.
+    Unknown { unclosed: usize },
+}
+
+const ISOLATION_MAX_STREAMS: usize = 100_000;
+const ISOLATION_MAX_BYTES: usize = 128 * 1024 * 1024;
+const ISOLATION_MAX_OPS: usize = 1_000_000;
+const ISOLATION_MAX_DEPTH: usize = 10_000;
+
+fn isolation(doc: &Document, list: &[Object]) -> Isolation {
+    let unknown = Isolation::Unknown { unclosed: 0 };
+    if list.len() > ISOLATION_MAX_STREAMS {
+        return unknown;
+    }
+    let mut remaining = ISOLATION_MAX_BYTES;
+    let mut data = Vec::with_capacity(list.len());
+    for object in list {
+        let resolved = doc.resolve(object);
+        let Object::Stream(stream) = &*resolved else { return unknown };
+        let Ok(bytes) = stream.decoded_within(remaining) else { return unknown };
+        let Some(left) = remaining.checked_sub(bytes.len().saturating_add(1)) else { return unknown };
+        remaining = left;
+        data.push(bytes);
+    }
+    let pieces = pdfcraft_content::Pieces::join(&data);
+    let parsed = pieces.parse();
+    if parsed.skipped != 0 || parsed.ops.len() > ISOLATION_MAX_OPS {
+        return unknown;
+    }
+    let edges = pieces.comment_edges(&parsed);
+    let (mut text_open, mut path_open, mut dirty, mut malformed) = (false, false, false, false);
+    let mut stack: Vec<usize> = Vec::new();
+    let mut split = 0;
+    let mut previous_last = None;
+    let mut wrappers = Vec::new();
+    for op in &parsed.ops {
+        let (first, last) = pieces.pieces_of(op);
+        // A wrapper can only go in before a whole stream, at the top level, between operators,
+        // and where no comment runs into the stream (it would swallow the wrapper's `q`).
+        if stack.is_empty()
+            && !text_open
+            && !path_open
+            && !dirty
+            && previous_last.is_none_or(|previous| first > previous)
+            && !edges.get(first).is_some_and(|edge| edge.0)
+        {
+            split = first;
+        }
+        previous_last = Some(last);
+        match op.op.as_slice() {
+            b"BT" if !text_open => text_open = true,
+            b"ET" if text_open => text_open = false,
+            b"BT" | b"ET" => malformed = true,
+            b"m" | b"l" | b"c" | b"v" | b"y" | b"h" | b"re" | b"W" | b"W*" => path_open = true,
+            b"n" | b"S" | b"s" | b"f" | b"F" | b"f*" | b"B" | b"B*" | b"b" | b"b*" => path_open = false,
+            _ => {}
+        }
+        match op.op.as_slice() {
+            b"q" if op.operands.is_empty() && stack.len() < ISOLATION_MAX_DEPTH => stack.push(first),
+            b"Q" if op.operands.is_empty() => match stack.pop() {
+                Some(open) => {
+                    // Only a standalone PdfCraft wrapper pair may later be removed again.
+                    let wrap = |i: usize| list.get(i).is_some_and(|o| stream_tag(doc, o).as_deref() == Some("Wrap"));
+                    if wrap(open)
+                        && wrap(first)
+                        && data.get(open).is_some_and(|d| d == WRAP_OPEN)
+                        && data.get(first).is_some_and(|d| is_wrap_close(d))
+                    {
+                        wrappers.push((open, first));
+                    }
+                }
+                None => malformed = true,
+            },
+            b"q" | b"Q" => malformed = true,
+            _ if stack.is_empty() => dirty = true,
+            _ => {}
+        }
+    }
+    if malformed || text_open || path_open || !stack.is_empty() {
+        return Isolation::Unknown { unclosed: if malformed { 0 } else { stack.len() } };
+    }
+    let comment_open = edges.last().is_some_and(|edge| edge.1);
+    Isolation::Clean { suffix: (dirty || comment_open).then_some(split), wrappers }
+}
+
 /// Put a mark's content on a page: behind (prepended) or on top (appended, after wrapping the
 /// original content in q/Q).
 fn place(doc: &mut Document, page: &pdfcraft_model::Page, kind: MarkKind, content: Vec<u8>, behind: bool) -> Result<(), EditError> {
     place_tagged(doc, page, kind.tag(), content, behind)
 }
 
-/// Put content on a page, tagged `tag` (see [`place`]).
+/// Put content on a page, tagged `tag` (see [`place`]). On top, whatever graphics state the
+/// content before leaves set (a `cm`, a clip, text state…) must not reach the mark, including
+/// content appended after an earlier PdfCraft wrapper by another tool (#3084): the stretch of
+/// content that leaves state set is wrapped in q/Q, once.
 fn place_tagged(doc: &mut Document, page: &pdfcraft_model::Page, tag: &str, content: Vec<u8>, behind: bool) -> Result<(), EditError> {
     let mut list = contents(doc, page)?;
+    let wrap = if behind {
+        None
+    } else {
+        match isolation(doc, &list) {
+            Isolation::Clean { suffix, .. } => suffix.map(|split| (split, 0)),
+            // Content that can't be read precisely is wrapped whole, as before: after the
+            // behind-marks at the start. A `q` it leaves open is closed at its end, where
+            // closing it changes nothing already drawn.
+            Isolation::Unknown { unclosed } => {
+                let behind_kinds = [MarkKind::Background.tag(), MarkKind::Watermark.tag()];
+                let split = list.iter().position(|o| !stream_tag(doc, o).is_some_and(|t| behind_kinds.contains(&t.as_str()))).unwrap_or(list.len());
+                (split < list.len()).then_some((split, unclosed))
+            }
+        }
+    };
     let mark = Object::Ref(doc.add(Object::Stream(Stream::flate(tagged(tag), &content))));
     if behind {
         list.insert(0, mark);
     } else {
-        let wrapped = list.iter().any(|o| stream_tag(doc, o).as_deref() == Some("Wrap"));
-        let original = list.iter().any(|o| stream_tag(doc, o).is_none());
-        if !wrapped && original {
+        if let Some((split, unclosed)) = wrap {
+            let mut close_bytes = b"\nQ".repeat(unclosed);
+            close_bytes.extend_from_slice(WRAP_CLOSE);
             let open = Object::Ref(doc.add(Object::Stream(Stream::from_raw(tagged("Wrap"), WRAP_OPEN.to_vec()))));
-            let close = Object::Ref(doc.add(Object::Stream(Stream::from_raw(tagged("Wrap"), WRAP_CLOSE.to_vec()))));
-            // Behind-marks stay outside the wrapper.
-            let split = list.iter().position(|o| stream_tag(doc, o).is_none()).unwrap_or(list.len());
-            list.insert(split, open);
+            let close = Object::Ref(doc.add(Object::Stream(Stream::from_raw(tagged("Wrap"), close_bytes))));
+            list.insert(split.min(list.len()), open);
             list.push(close);
         }
         list.push(mark);
@@ -613,8 +754,9 @@ pub fn add_background(doc: &mut Document, pages: &[usize], bg: &Background, repl
     Ok(())
 }
 
-/// Remove marks of `kind` from `pages`; returns how many were removed. When no mark is left on
-/// top of a page, the q/Q wrapper goes too, restoring the original content list.
+/// Remove marks of `kind` from `pages`; returns how many were removed. Wrappers left with
+/// nothing after them go too, restoring the original content list; a wrapper that content
+/// after it still relies on (another tool's appended stream) stays.
 pub fn remove_marks(doc: &mut Document, pages: &[usize], kind: MarkKind) -> Result<usize, EditError> {
     let all = page_list(doc);
     check(pages, all.len())?;
@@ -625,12 +767,41 @@ pub fn remove_marks(doc: &mut Document, pages: &[usize], kind: MarkKind) -> Resu
         let before = list.len();
         let mut kept: Vec<Object> = list.into_iter().filter(|o| stream_tag(doc, o).as_deref() != Some(kind.tag())).collect();
         removed += before - kept.len();
-        // Marks on top come after the closing wrapper; without any, the wrapper has no purpose.
-        let is_wrap = |o: &Object| stream_tag(doc, o).as_deref() == Some("Wrap");
-        let close = kept.iter().rposition(&is_wrap);
-        let marks_on_top = close.is_some_and(|c| kept[c + 1..].iter().any(|o| stream_tag(doc, o).is_some_and(|t| t != "Wrap")));
-        if !marks_on_top {
-            kept.retain(|o| !is_wrap(o));
+        // Strip only wrapper pairs whose close ends the list (after stripping the pairs after
+        // it): nothing comes after them to need the state they restore. Pairs come from the
+        // operators; for content that can't be read that precisely, from the wrapper streams
+        // alone, so updating a mark there doesn't nest another wrapper each time.
+        if before != kept.len() {
+            let wrappers = match isolation(doc, &kept) {
+                Isolation::Clean { wrappers, .. } => wrappers,
+                Isolation::Unknown { .. } => {
+                    let mut opens = Vec::new();
+                    let mut pairs = Vec::new();
+                    for (i, o) in kept.iter().enumerate() {
+                        match wrapper_role(doc, o) {
+                            Some(true) => opens.push(i),
+                            Some(false) => pairs.extend(opens.pop().map(|open| (open, i))),
+                            None => {}
+                        }
+                    }
+                    pairs
+                }
+            };
+            let pairs: std::collections::HashMap<usize, usize> = wrappers.into_iter().map(|(open, close)| (close, open)).collect();
+            let mut discarded = std::collections::HashSet::new();
+            let mut end = kept.len();
+            while let Some(close) = end.checked_sub(1) {
+                if discarded.contains(&close) {
+                    end = close;
+                } else if let Some(&open) = pairs.get(&close) {
+                    discarded.insert(open);
+                    discarded.insert(close);
+                    end = close;
+                } else {
+                    break;
+                }
+            }
+            kept = kept.into_iter().enumerate().filter(|(i, _)| !discarded.contains(i)).map(|(_, o)| o).collect();
         }
         if before != kept.len() {
             doc.update_dict(page.obj, |d| d.set(b"Contents".to_vec(), Object::Array(kept)))?;
diff --git a/crates/edit/src/tests.rs b/crates/edit/src/tests.rs
index b542142df..88e3d7806 100644
--- a/crates/edit/src/tests.rs
+++ b/crates/edit/src/tests.rs
@@ -77,7 +77,8 @@ fn header_and_footer_are_drawn_in_display_space_and_wrap_the_original_content()
     let s0 = streams(&doc, 0);
     // q-wrapper, original, Q-wrapper, header/footer.
     assert_eq!(s0.len(), 4, "{s0:?}");
-    assert_eq!((s0[0].as_str(), s0[2].as_str()), ("q %PdfCraft\n", "Q %PdfCraft\n"));
+    // The close starts on a new line, so a comment the original ends in can't swallow it.
+    assert_eq!((s0[0].as_str(), s0[2].as_str()), ("q %PdfCraft\n", "\nQ %PdfCraft\n"));
     let mark = &s0[3];
     assert!(mark.contains("/PCMark /HeaderFooter") && mark.contains("(Page 1 of 3) Tj") && mark.contains("(Confidential \\(draft\\)) Tj"), "{mark}");
     assert!(mark.contains("1 0 0 1 0 0 cm"), "upright page: identity");
@@ -4249,3 +4250,226 @@ fn japanese_paragraphs_wrap_between_characters_without_closing_marks_at_a_row_st
         }
     }
 }
+
+/// Small graphics-state oracle for synthetic streams: every tracked state change must
+/// have been restored when a probe XObject would draw. No external assets are involved.
+fn probe_states(doc: &Document) -> Vec<std::collections::BTreeMap<Vec<u8>, Vec<Object>>> {
+    let bytes = streams(doc, 0);
+    let joined = pdfcraft_content::Pieces::join(&bytes);
+    let mut state = std::collections::BTreeMap::new();
+    let mut stack = Vec::new();
+    let mut probes = Vec::new();
+    for op in joined.parse().ops {
+        match op.op.as_slice() {
+            b"q" => stack.push(state.clone()),
+            b"Q" => state = stack.pop().expect("balanced graphics state"),
+            b"cm" | b"W" | b"W*" | b"Tz" | b"Tc" | b"Tw" | b"Tr" | b"cs" => {
+                state.insert(op.op, op.operands);
+            }
+            b"Do" if op.name(0) == Some(b"PCProbe") => probes.push(state.clone()),
+            _ => {}
+        }
+    }
+    probes
+}
+
+fn isolation_fixture(parts: &[(&str, &str)]) -> Document {
+    let mut doc = fixture();
+    let page = page_list(&doc).remove(0);
+    let list = parts
+        .iter()
+        .map(|(tag, bytes)| {
+            Object::Ref(doc.add(Object::Stream(Stream::from_raw(if tag.is_empty() { Dict::new() } else { tagged(tag) }, bytes.as_bytes().to_vec()))))
+        })
+        .collect();
+    doc.update_dict(page.obj, |d| d.set(b"Contents".to_vec(), Object::Array(list))).unwrap();
+    doc
+}
+
+#[test]
+fn new_marks_isolate_state_appended_after_old_wrappers() {
+    for dirt in ["0.5 0 0 0.5 0 0 cm", "0 0 200 200 re W n", "50 Tz", "5 Tc 20 Tw", "3 Tr", "/Pattern cs"] {
+        for tag in ["", "OCR", "Wrap"] {
+            let mut doc = isolation_fixture(&[
+                ("Wrap", "q %PdfCraft\n"),
+                ("", "2 0 0 2 0 0 cm"),
+                ("Wrap", "Q %PdfCraft\n"),
+                ("Added", "q /PCProbe Do Q"),
+                (tag, dirt),
+            ]);
+            let before = probe_states(&doc);
+            stamp(&mut doc, 0, "Probe", b"q /PCProbe Do Q\n".to_vec()).unwrap();
+            let after = probe_states(&reopen(&doc));
+            assert_eq!(&after[..before.len()], &before, "existing content must not change");
+            assert!(after.last().unwrap().is_empty(), "tag={tag}, dirt={dirt}: {after:?}");
+        }
+    }
+}
+
+#[test]
+fn new_marks_isolate_dirty_tagged_only_pages() {
+    let mut doc = isolation_fixture(&[("OCR", "50 Tz 5 Tc 20 Tw")]);
+    stamp(&mut doc, 0, "Probe", b"q /PCProbe Do Q\n".to_vec()).unwrap();
+    assert!(probe_states(&doc).last().unwrap().is_empty());
+}
+
+#[test]
+fn new_marks_do_not_accumulate_wrappers_for_self_contained_marks() {
+    let mut doc = isolation_fixture(&[("", "2 0 0 2 0 0 cm")]);
+    for _ in 0..10 {
+        stamp(&mut doc, 0, "Probe", b"q /PCProbe Do Q\n".to_vec()).unwrap();
+    }
+    assert_eq!(streams(&doc, 0).len(), 13);
+    assert!(probe_states(&doc).iter().all(|s| s.is_empty()));
+}
+
+#[test]
+fn new_marks_close_wrapper_after_an_unterminated_comment() {
+    let mut doc = isolation_fixture(&[("", "50 Tz % no final newline")]);
+    stamp(&mut doc, 0, "Probe", b"q /PCProbe Do Q\n".to_vec()).unwrap();
+    // Check literal concatenation too: a separator must exist in the saved stream itself,
+    // not just in the inspection parser, or the comment can swallow the closing Q.
+    let bytes = streams(&doc, 0).concat();
+    let parsed = pdfcraft_content::parse(bytes.as_bytes());
+    assert_eq!(parsed.ops.iter().filter(|op| op.is("Q")).count(), 2);
+    assert!(probe_states(&doc).last().unwrap().is_empty());
+}
+
+#[test]
+fn new_marks_wrap_unbalanced_graphics_state_whole_without_changing_it() {
+    // Content that can't be isolated precisely is wrapped whole, as before #3084, instead of
+    // refusing: redaction stamps its boxes after removing the text, so it can't back out.
+    for (data, probe_clean) in [("q 50 Tz", true), ("50 Tz q", true), ("q q Q", true), ("Q 50 Tz", false), ("q Q Q 50 Tz", false)] {
+        let mut doc = isolation_fixture(&[("Wrap", data)]);
+        let page = page_list(&doc).remove(0);
+        place_tagged(&mut doc, &page, "Probe", b"q /PCProbe Do Q".to_vec(), false).unwrap();
+        let after = streams(&doc, 0);
+        assert_eq!(after.len(), 4, "{data}: {after:?}");
+        assert_eq!((after[0].as_str(), after[1].as_str()), ("q %PdfCraft\n", data), "{data}");
+        // A `q` the content leaves open is closed after it, so the mark starts clean. A stray
+        // `Q` pops the wrapper itself: nothing placed after it can undo that.
+        let probe = probe_states_lenient(&doc);
+        assert_eq!(probe.last().unwrap().is_empty(), probe_clean, "{data}: {after:?}");
+    }
+}
+
+/// [`probe_states`] for unbalanced content: a `Q` with nothing saved leaves the state as is,
+/// as renderers do.
+fn probe_states_lenient(doc: &Document) -> Vec<std::collections::BTreeMap<Vec<u8>, Vec<Object>>> {
+    let joined = pdfcraft_content::Pieces::join(&streams(doc, 0));
+    let mut state = std::collections::BTreeMap::new();
+    let mut stack = Vec::new();
+    let mut probes = Vec::new();
+    for op in joined.parse().ops {
+        match op.op.as_slice() {
+            b"q" => stack.push(state.clone()),
+            b"Q" => state = stack.pop().unwrap_or(state),
+            b"cm" | b"W" | b"W*" | b"Tz" | b"Tc" | b"Tw" | b"Tr" | b"cs" => {
+                state.insert(op.op, op.operands);
+            }
+            b"Do" if op.name(0) == Some(b"PCProbe") => probes.push(state.clone()),
+            _ => {}
+        }
+    }
+    probes
+}
+
+#[test]
+fn new_marks_preserve_cross_stream_operands_and_q_pairs() {
+    let mut doc = isolation_fixture(&[("", "q 2 0 0 2"), ("", "0 0 cm Q 50"), ("", "Tz")]);
+    stamp(&mut doc, 0, "Probe", b"q /PCProbe Do Q\n".to_vec()).unwrap();
+    assert!(probe_states(&doc).last().unwrap().is_empty());
+}
+
+#[test]
+fn removing_marks_keeps_wrappers_needed_by_later_external_content() {
+    let mut doc = isolation_fixture(&[
+        ("Wrap", "q %PdfCraft\n"),
+        ("", "2 0 0 2 0 0 cm"),
+        ("Wrap", "Q %PdfCraft\n"),
+        ("HeaderFooter", "q /PCProbe Do Q"),
+        ("", "/PCProbe Do"),
+    ]);
+    remove_marks(&mut doc, &[0], MarkKind::HeaderFooter).unwrap();
+    assert_eq!(probe_states(&doc).len(), 1);
+    assert!(probe_states(&doc)[0].is_empty(), "the external content still needs the original reset");
+}
+
+#[test]
+fn new_marks_wrap_unfinished_text_paths_and_operands_whole() {
+    for data in ["BT", "ET", "BT BT ET", "0 0 10 10 re", "q 0 0 m Q", "50"] {
+        let mut doc = isolation_fixture(&[("Background", "q Q"), ("", data)]);
+        let page = page_list(&doc).remove(0);
+        place_tagged(&mut doc, &page, "Probe", b"q /PCProbe Do Q".to_vec(), false).unwrap();
+        // The behind-mark stays outside the wrapper and the content itself is untouched.
+        assert_eq!(streams(&doc, 0), ["q Q", "q %PdfCraft\n", data, "\nQ %PdfCraft\n", "q /PCProbe Do Q"], "{data}");
+    }
+}
+
+#[test]
+fn new_marks_do_not_reveal_cross_stream_comments() {
+    let mut doc = isolation_fixture(&[("", "q 50 Tz % comment continues"), ("", "Q 20 Tc\nQ 5 Tw")]);
+    stamp(&mut doc, 0, "Probe", b"q /PCProbe Do Q\n".to_vec()).unwrap();
+    assert!(probe_states(&doc).last().unwrap().is_empty());
+    let joined = pdfcraft_content::Pieces::join(&streams(&doc, 0));
+    assert!(!joined.parse().ops.iter().any(|op| op.is("Tc")), "commented content must remain inert");
+}
+
+#[test]
+fn new_marks_follow_clean_streams_ending_in_comments() {
+    let mut doc = isolation_fixture(&[("Added", "q 50 Tz Q % no newline")]);
+    stamp(&mut doc, 0, "Probe", b"q /PCProbe Do Q\n".to_vec()).unwrap();
+    assert_eq!(probe_states(&doc).len(), 1, "the new mark must not be swallowed by a comment");
+    assert!(probe_states(&doc)[0].is_empty());
+}
+
+#[test]
+fn removing_marks_does_not_strip_arbitrary_wrap_tagged_content() {
+    let mut doc = isolation_fixture(&[("Wrap", "q /PCProbe Do Q"), ("HeaderFooter", "q Q")]);
+    assert_eq!(remove_marks(&mut doc, &[0], MarkKind::HeaderFooter).unwrap(), 1);
+    assert_eq!(probe_states(&doc).len(), 1);
+}
+
+#[test]
+fn removing_marks_strips_nested_trailing_wrapper_pairs() {
+    let mut doc = isolation_fixture(&[
+        ("Wrap", "q %PdfCraft\n"),
+        ("Wrap", "q %PdfCraft\n"),
+        ("", "2 0 0 2 0 0 cm"),
+        ("Wrap", "Q %PdfCraft\n"),
+        ("Wrap", "Q %PdfCraft\n"),
+        ("HeaderFooter", "q Q"),
+    ]);
+    assert_eq!(remove_marks(&mut doc, &[0], MarkKind::HeaderFooter).unwrap(), 1);
+    assert_eq!(streams(&doc, 0), ["2 0 0 2 0 0 cm"]);
+}
+
+#[test]
+fn updating_marks_on_unreadable_content_does_not_nest_wrappers() {
+    for data in ["q 50 Tz", "Q 50 Tz", "BT"] {
+        let mut doc = isolation_fixture(&[("", data)]);
+        let page = page_list(&doc).remove(0);
+        for _ in 0..3 {
+            place_tagged(&mut doc, &page, MarkKind::HeaderFooter.tag(), b"q /PCProbe Do Q".to_vec(), false).unwrap();
+            assert_eq!(streams(&doc, 0).len(), 4, "{data}: {:?}", streams(&doc, 0));
+            assert_eq!(remove_marks(&mut doc, &[0], MarkKind::HeaderFooter).unwrap(), 1);
+            assert_eq!(streams(&doc, 0), [data], "{data}: the original list comes back");
+        }
+    }
+}
+
+#[test]
+fn removing_marks_strips_wrappers_that_closed_open_state() {
+    let mut doc = isolation_fixture(&[("", "q 2 0 0 2 0 0 cm")]);
+    stamp(&mut doc, 0, "Probe", b"q /PCProbe Do Q\n".to_vec()).unwrap();
+    assert!(probe_states(&doc).last().unwrap().is_empty());
+    // Now balanced, the page reads cleanly: the close (with its extra `Q`) still pairs.
+    let page = page_list(&doc).remove(0);
+    place_tagged(&mut doc, &page, MarkKind::Watermark.tag(), b"q /PCProbe Do Q\n".to_vec(), false).unwrap();
+    assert_eq!(streams(&doc, 0).len(), 5, "no second wrapper: {:?}", streams(&doc, 0));
+    let mut doc = isolation_fixture(&[("", "q 2 0 0 2 0 0 cm")]);
+    let page = page_list(&doc).remove(0);
+    place_tagged(&mut doc, &page, MarkKind::Watermark.tag(), b"q /PCProbe Do Q\n".to_vec(), false).unwrap();
+    assert_eq!(remove_marks(&mut doc, &[0], MarkKind::Watermark).unwrap(), 1);
+    assert_eq!(streams(&doc, 0), ["q 2 0 0 2 0 0 cm"]);
+}

From 9b4af15b21c6daa961a570d24550c7c6b51f09b0 Mon Sep 17 00:00:00 2001
From: skylar taylor-barrick <hi@skylar.cc>
Date: Sun, 18 Oct 2026 00:27:50 +0200
Subject: [PATCH 3/3] fix(edit): read marked content that spans content streams
 in one pass (#3081)

reading_lines grouped the joined operators by the stream their first token
is in and walked each group on its own. A marked-content sequence opened in
one stream (its /ActualText dictionary, or the whole BDC) and closed in the
next lost its replacement text: the export read "Glyphs" where every reader
of the joined streams reads "Replacement text".

The page's operators are now walked once. Each shown text still counts as
the stream its operator starts in, and text from another stream still starts
a new line, as before.
---
 crates/audit/src/tests.rs | 10 ++++++++++
 crates/edit/src/text.rs   | 32 +++++++++++++++++---------------
 2 files changed, 27 insertions(+), 15 deletions(-)

diff --git a/crates/audit/src/tests.rs b/crates/audit/src/tests.rs
index 64ea05bde..63d9220cc 100644
--- a/crates/audit/src/tests.rs
+++ b/crates/audit/src/tests.rs
@@ -518,4 +518,14 @@ fn reading_blocks_respect_stream_comments_and_split_operands() {
     let doc = open(two_streams(b"BT /F1 24 Tf 72 700 Td (Split operand)", b"Tj ET"));
     let text: String = pdfcraft_edit::reading_blocks(&doc, 0).unwrap().into_iter().map(|block| block.editor_text).collect();
     assert_eq!(text, "Split operand");
+    // Marked content opened in one stream applies to text in the next: its /ActualText replaces
+    // the glyphs, as when the streams are read joined.
+    for (s1, s2) in [
+        (b"BT /F1 24 Tf 72 700 Td /Span <</ActualText (Replacement text)".as_slice(), b">> BDC (Glyphs) Tj EMC ET".as_slice()),
+        (b"BT /F1 24 Tf 72 700 Td /Span <</ActualText (Replacement text)>> BDC", b"(Glyphs) Tj EMC ET"),
+    ] {
+        let doc = open(two_streams(s1, s2));
+        let text: String = pdfcraft_edit::reading_blocks(&doc, 0).unwrap().into_iter().map(|block| block.editor_text).collect();
+        assert_eq!(text, "Replacement text", "{}", String::from_utf8_lossy(s1));
+    }
 }
diff --git a/crates/edit/src/text.rs b/crates/edit/src/text.rs
index 93d1b54fc..916aaeadd 100644
--- a/crates/edit/src/text.rs
+++ b/crates/edit/src/text.rs
@@ -1237,12 +1237,14 @@ fn reading_lines(doc: &Document, page: usize) -> Result<Vec<TextLine>, EditError
         path: Vec<pdfcraft_cos::ObjRef>,
         visits: usize,
     }
-    fn walk(w: &mut Walk, ops: &[Op], resources: &Dict, carry: &mut Carry, stream: usize) {
+    /// `stream` gives the stream number of the operator at an index of `ops`.
+    fn walk(w: &mut Walk, ops: &[Op], resources: &Dict, carry: &mut Carry, stream: &dyn Fn(usize) -> usize) {
         let fonts_res = resources.get(b"Font").map(|f| w.doc.resolve(f)).and_then(|f| f.as_dict().cloned()).unwrap_or_default();
         let mut cache = HashMap::new();
         let mut invoked = Vec::new();
         let shown = interpret(w.doc, ops, &fonts_res, &mut cache, carry, Some(&mut invoked), true);
         let mut last = None;
+        let mut last_stream = None;
         let mut forms = invoked.into_iter().peekable();
         for s in shown {
             while let Some((_, name, ts)) = forms.next_if(|f| f.0 < s.op) {
@@ -1250,7 +1252,12 @@ fn reading_lines(doc: &Document, page: usize) -> Result<Vec<TextLine>, EditError
                 // Text after a form starts a new line.
                 last = None;
             }
-            add_shown(&mut w.lines, &mut last, s, stream);
+            let si = stream(s.op);
+            // Text from another stream starts a new line, as when each stream was read alone.
+            if last_stream.replace(si).is_some_and(|prev| prev != si) {
+                last = None;
+            }
+            add_shown(&mut w.lines, &mut last, s, si);
         }
         for (_, name, ts) in forms {
             enter(w, resources, &name, ts);
@@ -1266,7 +1273,7 @@ fn reading_lines(doc: &Document, page: usize) -> Result<Vec<TextLine>, EditError
         if let Some(r) = form.obj {
             w.path.push(r);
         }
-        walk(w, &ops, &form.resources, &mut carry, stream);
+        walk(w, &ops, &form.resources, &mut carry, &|_| stream);
         if form.obj.is_some() {
             w.path.pop();
         }
@@ -1276,19 +1283,14 @@ fn reading_lines(doc: &Document, page: usize) -> Result<Vec<TextLine>, EditError
     let streams = content_streams(doc, &p.dict);
     let mut w = Walk { doc, lines: Vec::new(), next_stream: streams.len(), path: Vec::new(), visits: 0 };
     let mut carry = Carry::new();
-    // Read the page's streams as the one stream they are, as rendering and editing do: a
-    // comment or an operator's operands can run on from one stream into the next. Each operator
-    // still counts as its first stream's, which keeps lines from different streams apart.
+    // Read the page's streams as the one stream they are, in one pass, as rendering and editing
+    // do: a comment, an operator's operands or a marked-content sequence (its /ActualText too)
+    // can run on from one stream into the next. Text still counts as the stream its operator
+    // starts in, which keeps lines from different streams apart.
     let pieces = Pieces::join(&streams.into_iter().map(|(_, data)| data).collect::<Vec<_>>());
-    let mut grouped: Vec<Vec<Op>> = (0..pieces.len()).map(|_| Vec::new()).collect();
-    for op in pieces.parse().ops {
-        if let Some(group) = grouped.get_mut(pieces.pieces_of(&op).0) {
-            group.push(op);
-        }
-    }
-    for (si, ops) in grouped.iter().enumerate() {
-        walk(&mut w, ops, &res, &mut carry, si);
-    }
+    let ops = pieces.parse().ops;
+    let stream_of = |i: usize| ops.get(i).map_or(0, |op| pieces.pieces_of(op).0);
+    walk(&mut w, &ops, &res, &mut carry, &stream_of);
     let mut lines = w.lines;
     // A visual-order Indic font draws pre-base vowel signs before their consonant.
     for l in lines.iter_mut().filter(|l| l.visual_order && !l.actual_text) {