M7: paragraph edits keep the advance of the text they drop (edit.text-edit) (#2968)

crates/edit/src/tests.rs

@@ -9684,6 +9684,102 @@ fn a_clipping_copy_on_the_same_baseline_is_refused() {
     assert_eq!(text::text_lines(&doc, 0).unwrap().len(), 2, "refused means untouched");
 }
 
+/// `'` moves to the next line before it shows its text, and `"` also sets the word and character
+/// spacing (ISO 32000-2 §9.4.3, Table 107). Rewriting a paragraph drawn with them drops the
+/// operator but must keep what it did: text after it, positioned from that line or using that
+/// spacing, stays exactly where and how it was. Both the single-style paragraph path and the
+/// region path (a draft with a line break) are checked.
+#[test]
+fn rewriting_a_paragraph_drawn_with_quote_operators_keeps_their_line_move_and_spacing() {
+    let cases = [
+        // The next line is placed relative to the line `'` moved to.
+        "BT /F1 12 Tf 14 TL 72 714 Td (Target line here) ' 0 -100 Td (Footer stays put) Tj ET",
+        // The same with `"`, whose spacing the footer also inherits.
+        "BT /F1 12 Tf 14 TL 72 714 Td 3 2 (Target line here) \" 0 -100 Td (Footer stays put) Tj ET",
+        // Spacing set by `"` carries over into the next text object.
+        "BT /F1 12 Tf 14 TL 72 714 Td 3 2 (Target line here) \" ET BT 72 600 Td (Footer stays put) Tj ET",
+        // A split text object: text before the paragraph stays first, then the `'` lines go.
+        "BT /F1 12 Tf 14 TL 72 760 Td (Heading words) Tj 0 -46 Td (Target line here) Tj (more target) ' 0 -100 Td (Footer stays put) Tj ET",
+        // Split at a `'`: the rewrite's `Tm` there is already past its line move.
+        "BT /F1 12 Tf 14 TL 72 760 Td (Heading words) Tj 0 -32 Td (Target line here) ' (more target) ' 0 -100 Td (Footer stays put) Tj ET",
+    ];
+    for content in cases {
+        let footer = |doc: &Document| {
+            let lines = text::text_lines(doc, 0).unwrap();
+            let f = lines.iter().find(|l| l.text == "Footer stays put").unwrap_or_else(|| panic!("no footer in {content}"));
+            (f.rect, f.ink.clone())
+        };
+        let original = text_page(content);
+        let before = footer(&original);
+        let target = text::text_blocks(&original, 0).unwrap().iter().position(|b| b.text.starts_with("Target")).unwrap();
+        for draft in ["NEW TEXT", "NEW\nTEXT"] {
+            let mut doc = original.clone();
+            text::replace_block(&mut doc, 0, target, draft).unwrap();
+            let doc = reopen(&doc);
+            assert_eq!(footer(&doc), before, "{content} with {draft:?}");
+            let texts: Vec<String> = text::text_blocks(&doc, 0).unwrap().into_iter().map(|b| b.text).collect();
+            assert!(texts.iter().any(|t| t.contains("NEW")) && !texts.iter().any(|t| t.contains("Target")), "{content} with {draft:?}: {texts:?}");
+        }
+    }
+}
+
+/// [`text::replace_line`] also drops copies of the line drawn on the same baseline (a fake-bold
+/// overprint). A copy drawn with `'` or `"` must leave that operator's line move and spacing
+/// behind (ISO 32000-2 §9.4.3, Table 107), like the line's own first operator does: text after
+/// it is positioned from that line or uses that spacing. Each copy is tried as the target, so the
+/// one drawn with the quote operator is both the replaced line and the dropped copy.
+#[test]
+fn replacing_a_line_keeps_what_a_dropped_quote_copy_did() {
+    let cases = [
+        // The copy's `'` moves to the line the footer is placed from.
+        "BT /F1 12 Tf 14 TL 72 700 Td (Target line here) Tj ET BT 72.3 714 Td (Target line here) ' 0 -100 Td (Footer stays put) Tj ET",
+        // The copy's `"` sets the spacing the footer inherits in the next text object.
+        "BT /F1 12 Tf 0 TL 72 700 Td (Target line here) Tj ET BT 72.3 700 Td 3 2 (Target line here) \" ET BT 72 600 Td (Footer stays put) Tj ET",
+    ];
+    for content in cases {
+        let footer = |doc: &Document| {
+            let lines = text::text_lines(doc, 0).unwrap();
+            let f = lines.iter().find(|l| l.text == "Footer stays put").unwrap_or_else(|| panic!("no footer in {content}"));
+            (f.rect, f.ink.clone())
+        };
+        let original = text_page(content);
+        let before = footer(&original);
+        let targets: Vec<usize> =
+            text::text_lines(&original, 0).unwrap().iter().enumerate().filter(|(_, l)| l.text == "Target line here").map(|(i, _)| i).collect();
+        assert_eq!(targets.len(), 2, "{content}");
+        for target in targets {
+            let mut doc = original.clone();
+            text::replace_line(&mut doc, 0, target, "NEW TEXT").unwrap();
+            let doc = reopen(&doc);
+            assert_eq!(footer(&doc), before, "{content} replacing line {target}");
+            let texts: Vec<String> = text::text_lines(&doc, 0).unwrap().into_iter().map(|l| l.text).collect();
+            assert!(texts.iter().any(|t| t == "NEW TEXT") && !texts.iter().any(|t| t.contains("Target")), "{content}: {texts:?}");
+        }
+    }
+}
+
+/// A copy dropped with the line it overprints moved the pen by its text: a run after it in its
+/// text object, placed by that pen, stays where it was (ISO 32000-2 §9.4.4).
+#[test]
+fn replacing_a_line_keeps_the_advance_of_a_dropped_copy() {
+    for content in [
+        "BT /F1 12 Tf 72 700 Td (Target line here) Tj ET BT 72.3 700 Td (Target line here) Tj [-20000] TJ (Far) Tj ET",
+        "BT /F1 12 Tf 0 TL 72 700 Td (Target line here) Tj ET BT 72.3 700 Td (Target line here) ' [-20000] TJ (Far) Tj ET",
+    ] {
+        let original = text_page(content);
+        let place = |doc: &Document| text::text_lines(doc, 0).unwrap().into_iter().find(|l| l.text == "Far").map(|l| l.rect);
+        let before = place(&original).unwrap_or_else(|| panic!("Far is a line of its own in {content}"));
+        // The line drawn first, so the one followed by Far is the copy.
+        let target = text::text_lines(&original, 0).unwrap().iter().position(|l| l.text == "Target line here").unwrap();
+        let mut doc = original.clone();
+        text::replace_line(&mut doc, 0, target, "NEW TEXT").unwrap();
+        let doc = reopen(&doc);
+        let texts: Vec<String> = text::text_lines(&doc, 0).unwrap().into_iter().map(|l| l.text).collect();
+        assert!(!texts.iter().any(|t| t.contains("Target")), "{content}: the copy went too: {texts:?}");
+        assert_eq!(place(&doc), Some(before), "{content}");
+    }
+}
+
 /// #2512: a session's drafts are laid out from the document as it was opened, never from each
 /// other, and its commit writes what a one-shot rewrite writes, whatever was laid out before.
 #[test]
@@ -13610,6 +13706,87 @@ fn review_inside_scope_group_move_matches_direct_transform_under_outer_scale() {
     }
 }
 
+/// Each `Tj`/`TJ` moves the text matrix by the width of its text. A run shown later in the same
+/// text object without a `Td` or `Tm` of its own (a raised run in another colour, a column after
+/// a `TJ` gap) is placed by those advances. Rewriting the paragraph before it must keep them, as
+/// deleting a paragraph does: the run must not jump onto the new text. A kept run before the
+/// paragraph splits the text object, and what reopens it keeps that run's advance too.
+#[test]
+fn rewriting_a_paragraph_keeps_later_runs_on_its_baseline_in_place() {
+    let cases = [
+        ("BT /F1 12 Tf 72 700 Td (Target words) Tj 1 0 0 rg 3 Ts (Red) Tj ET", "Red"),
+        ("BT /F1 12 Tf 72 700 Td (Target words) Tj [-20000] TJ (Far) Tj ET", "Far"),
+        // Several dropped runs: each one's advance is kept.
+        ("BT /F1 12 Tf 72 700 Td (Target ) Tj (wor) Tj (ds) Tj [-20000] TJ (Far) Tj ET", "Far"),
+        // A kept run before the paragraph on its baseline: the text object is split there, and
+        // the pen it had reached is kept as well as the line matrix.
+        ("BT /F1 12 Tf 72 700 Td (Left) Tj [-20000] TJ (Target words) Tj [-20000] TJ (Far) Tj ET", "Far"),
+        ("BT /F1 12 Tf 72 700 Td (Left) Tj [-20000] TJ (Target ) Tj (words) Tj [-20000] TJ (Far) Tj ET", "Far"),
+        // The same with horizontal scaling and a later line placed from the line matrix.
+        ("BT /F1 12 Tf 80 Tz 14 TL 72 700 Td (Left) Tj [-20000] TJ (Target words) Tj [-20000] TJ (Far) Tj T* (Next) Tj ET", "Far"),
+        ("BT /F1 12 Tf 80 Tz 14 TL 72 700 Td (Left) Tj [-20000] TJ (Target words) Tj [-20000] TJ (Far) Tj T* (Next) Tj ET", "Next"),
+        // A `Q` puts back the text matrix its `q` saved: the `Tm` between them doesn't place `Far`.
+        ("BT /F1 12 Tf 72 700 Td (Target words) Tj q 1 0 0 1 300 300 Tm Q [-20000] TJ (Far) Tj ET", "Far"),
+        // A `Q` with nothing saved restores nothing: the advance is still kept.
+        ("BT /F1 12 Tf 72 700 Td (Target words) Tj Q [-20000] TJ (Far) Tj ET", "Far"),
+    ];
+    for (content, run) in cases {
+        let original = text_page(content);
+        let place = |doc: &Document| text::text_lines(doc, 0).unwrap().into_iter().find(|l| l.text == run).map(|l| l.rect);
+        let before = place(&original).unwrap_or_else(|| panic!("{run} is a line of its own in {content}"));
+        let target = text::text_blocks(&original, 0).unwrap().iter().position(|b| b.text == "Target words").unwrap();
+        for draft in ["NEW TEXT", "NEW\nTEXT"] {
+            let mut doc = original.clone();
+            text::replace_block(&mut doc, 0, target, draft).unwrap();
+            let after = place(&reopen(&doc)).unwrap_or_else(|| panic!("{run} is gone: {content} with {draft:?}"));
+            assert!(after.iter().zip(before).all(|(a, b)| (a - b).abs() < 1e-6), "{content} with {draft:?}: {before:?} -> {after:?}");
+        }
+    }
+}
+
+/// Vertical text advances down the column (ISO 32000-2 §9.4.4): runs dropped by a rewrite leave
+/// that advance, so a run later in the same text object stays where it was.
+#[test]
+fn rewriting_vertical_runs_keeps_a_later_run_in_its_column_in_place() {
+    // The second with a horizontal scaling (`Tz`), which a vertical advance doesn't take.
+    for content in [
+        "BT /V1 20 Tf 500 720 Td <0041> Tj <0042> Tj [-8000] TJ <0043> Tj ET",
+        "BT /V1 20 Tf 80 Tz 500 720 Td <0041> Tj <0042> Tj [-8000] TJ <0043> Tj ET",
+    ] {
+        vertical_runs_keep_a_later_run_in_place(content);
+    }
+}
+
+fn vertical_runs_keep_a_later_run_in_place(content: &str) {
+    let original = vertical_page(content);
+    let place = |doc: &Document| text::text_lines(doc, 0).unwrap().into_iter().find(|l| l.text == "C").map(|l| l.rect);
+    let before = place(&original).unwrap_or_else(|| panic!("C is a line of its own: {:?}", text::text_lines(&original, 0)));
+    let target = text::text_blocks(&original, 0).unwrap().iter().position(|b| b.text == "AB").unwrap();
+    for draft in [
+        "D", "D
+E",
+    ] {
+        let mut doc = original.clone();
+        text::replace_block(&mut doc, 0, target, draft).unwrap();
+        let after = place(&reopen(&doc)).unwrap_or_else(|| panic!("C is gone with {draft:?}"));
+        assert!(after.iter().zip(before).all(|(a, b)| (a - b).abs() < 1e-6), "{content} with {draft:?}: {before:?} -> {after:?}");
+    }
+}
+
+/// The advances read the glyphs without `/ActualText`, which can come to more text than the
+/// reading the edit was laid out from. Past the page's text budget that way, no advance is kept
+/// and the edit goes ahead, rather than refusing a page the reading allowed.
+#[test]
+fn dropped_advances_past_the_text_budget_keep_none_rather_than_refuse() {
+    let doc = text_page("BT /F1 12 Tf 72 700 Td (Drop) Tj [-20000] TJ (Far) Tj ET");
+    let ops = pdfcraft_content::parse(&page_content_bytes(&doc, 0)).ops;
+    let drop: std::collections::HashSet<usize> = ops.iter().position(|o| o.is("Tj")).into_iter().collect();
+    let page = pdfcraft_model::pages(&doc)[0].dict.clone();
+    let res = page.get(b"Resources").map(|r| doc.resolve(r)).and_then(|r| r.as_dict().cloned()).unwrap_or_default();
+    assert_eq!(text::dropped_advances_within(&doc, &ops, &res, &drop, None).len(), 1, "the advance Far relies on");
+    assert!(text::dropped_advances_within(&doc, &ops, &res, &drop, Some(2)).is_empty(), "too much text to read: none");
+}
+
 #[test]
 fn page_rules_refuse_unread_graphics_state() {
     let mut dict = Dict::new();

crates/edit/src/text.rs

@@ -55,9 +55,11 @@ use fallback::{
 use fallback::{add_type3_font, is_type3_fallback};
 pub(crate) use fallback::{glyph_path, type3_font_dict, unique_font_name};
 use interp::{Origin, Paint, union};
+#[cfg(test)]
+pub(crate) use lines::dropped_advances_within;
 pub(crate) use lines::{
-    ContentStream, FormBudget, Read, content_streams, content_streams_within, dict_in_place, drawn_before_damage, first_op_after_damage, form_call,
-    joined, resource_dict, rewritten_contents, splice,
+    ContentStream, FormBudget, Read, content_streams, content_streams_within, dict_in_place, drawn_before_damage, dropped_advances,
+    dropped_side_effects, first_op_after_damage, form_call, joined, reopen_text_object, resource_dict, rewritten_contents, splice,
 };
 pub use lines::{MAX_FORM_DEPTH, MAX_FORM_VISITS, glyph_text_lines, text_lines};
 use lines::{page_dict, word_lines};

crates/edit/src/text/blocks.rs

@@ -1,5 +1,5 @@
 use super::interp::{Carry, interpret};
-use super::lines::{content_streams, joined, page_dict, reading_lines, rewritten_contents, splice, text_lines};
+use super::lines::{content_streams, joined, page_dict, reading_lines, rewritten_contents, show_side_effects, splice, text_lines};
 use super::rewrite::{LineEdit, coincident_ops, rewrite_block};
 use super::{Document, EditError, HashMap, Object, Op, TextLine, group_blocks, regions};
 
@@ -315,13 +315,7 @@ pub fn clear_block(doc: &mut Document, page: usize, block: usize) -> Result<(),
         }
         let mut replacement = Vec::new();
         if let Some(op) = ops.get(s.op) {
-            if op.is("\"") {
-                replacement.push(Op::new("Tw", vec![op.operands.first().cloned().unwrap_or(Object::Int(0))]));
-                replacement.push(Op::new("Tc", vec![op.operands.get(1).cloned().unwrap_or(Object::Int(0))]));
-            }
-            if op.is("'") || op.is("\"") {
-                replacement.push(Op::new("T*", vec![]));
-            }
+            replacement.extend(show_side_effects(op));
         }
         replacement.push(Op::new("TJ", vec![Object::Array(vec![pdfcraft_content::num(adjustment)])]));
         patches.insert(s.op, replacement);

crates/edit/src/text/lines.rs

@@ -115,6 +115,146 @@ pub(crate) fn content_streams_within(doc: &Document, page: &Dict, budget: &mut D
     Ok(out)
 }
 
+/// What a text-showing operator does besides showing text (ISO 32000-2 §9.4.3, Table 107): `'`
+/// moves to the next line (`T*`), and `"` first sets the word and character spacing (`aw Tw`,
+/// `ac Tc`). Text after it relies on both, so a dropped `'` or `"` leaves these in its place.
+pub(crate) fn show_side_effects(op: &Op) -> Vec<Op> {
+    let mut out = Vec::new();
+    if op.is("\"") {
+        out.extend(op.num(0).map(|aw| Op::new("Tw", vec![pdfcraft_content::num(aw)])));
+        out.extend(op.num(1).map(|ac| Op::new("Tc", vec![pdfcraft_content::num(ac)])));
+    }
+    if op.is("'") || op.is("\"") {
+        out.push(Op::new("T*", vec![]));
+    }
+    out
+}
+
+/// For a paragraph or region rewrite: what dropped operator `i` must leave behind
+/// ([`show_side_effects`]), so the text after it keeps its line and spacing. `split_at` is the
+/// operator the text object was split at: the rewrite's `Tm` and state there already include
+/// that operator's effects.
+pub(crate) fn dropped_side_effects(ops: &[Op], i: usize, keep: bool, split_at: Option<usize>) -> Vec<Op> {
+    if keep || split_at == Some(i) {
+        return Vec::new();
+    }
+    ops.get(i).map(show_side_effects).unwrap_or_default()
+}
+
+/// For a paragraph or region rewrite that splits a text object: what reopens it after the
+/// rewritten paragraph, so the text after it starts where it did. `tlm` and `tm` are the line and
+/// text matrices where the paragraph began, and `size` and `scale` the font size (`Tf`) and
+/// horizontal scaling (`Tz` / 100) in force there. A `Tm` restores the line matrix, which a later
+/// `Td` or `T*` moves from; a kept run before the paragraph on the same baseline had already
+/// advanced the pen beyond it (ISO 32000-2 §9.4.4), so a numeric `TJ` then moves the text matrix
+/// alone by that advance. Only an advance along a horizontal baseline is expressible that way;
+/// one that isn't (a vertical run's, or one at a zero size) leaves the pen at the line matrix.
+pub(crate) fn reopen_text_object(tlm: [f64; 6], tm: [f64; 6], size: Option<f64>, scale: f64) -> Vec<Op> {
+    let n = pdfcraft_content::num;
+    let mut out = vec![Op::new("BT", vec![]), Op::new("Tm", tlm.iter().map(|v| n(*v)).collect())];
+    // tm = [1 0 0 1 tx ty] x tlm: solve for the advance (tx, ty) in text space.
+    let (dx, dy) = (tm[4] - tlm[4], tm[5] - tlm[5]);
+    let det = tlm[0] * tlm[3] - tlm[1] * tlm[2];
+    let tx = (dx * tlm[3] - dy * tlm[2]) / det;
+    let ty = (dy * tlm[0] - dx * tlm[1]) / det;
+    let denominator = size.unwrap_or(0.0) * scale;
+    let adjustment = -1000.0 * tx / denominator;
+    if tx.is_finite() && ty.is_finite() && tx.abs() > 1e-9 && ty.abs() <= 1e-9 && denominator != 0.0 && adjustment.is_finite() {
+        out.push(Op::new("TJ", vec![Object::Array(vec![n(adjustment)])]));
+    }
+    out
+}
+
+/// For a paragraph or region rewrite: a numeric `TJ` per dropped show operator in `drop`, moving
+/// the text matrix as far as that operator's text did without drawing anything (as
+/// [`super::clear_block`] does). Text shown later in the same text object without its own `Td`
+/// or `Tm`, such as a run in another style or column on the same baseline, then stays where it
+/// was. Only an advance such a run relies on is kept: none when the text object ends, or its next
+/// kept run starts a line of its own (`Td`, `TD`, `Tm`, `T*`, `'`, `"`), first. An advance a `TJ`
+/// can't express (spacing at a zero font size) is left out. `resources` is the page's resource
+/// dictionary. This reads the glyphs without `/ActualText`, which can come to more text than the
+/// reading the edit was laid out from; a page whose text that way exceeds the page's text budget
+/// keeps no advances rather than refusing an edit the reading allowed.
+pub(crate) fn dropped_advances(doc: &Document, ops: &[Op], resources: &Dict, drop: &std::collections::HashSet<usize>) -> HashMap<usize, Op> {
+    dropped_advances_within(doc, ops, resources, drop, None)
+}
+
+/// [`dropped_advances`] with `text_left` in place of the page's text budget (tests make it small).
+pub(crate) fn dropped_advances_within(
+    doc: &Document,
+    ops: &[Op],
+    resources: &Dict,
+    drop: &std::collections::HashSet<usize>,
+    text_left: Option<usize>,
+) -> HashMap<usize, Op> {
+    let mut out = HashMap::new();
+    let mut carry = Carry::new();
+    if let Some(left) = text_left {
+        carry.text_left = left;
+    }
+    let follows = kept_run_follows(ops, drop);
+    let Ok(shown) = interpret(doc, ops, resources, &mut HashMap::new(), &mut carry, None, None) else {
+        return out;
+    };
+    for s in shown {
+        if !drop.contains(&s.op) || s.advance == 0.0 || !follows.get(s.op).copied().unwrap_or(false) {
+            continue;
+        }
+        let denominator = s.state.size * s.state.scale;
+        let adjustment = -1000.0 * s.advance / denominator;
+        if denominator != 0.0 && adjustment.is_finite() {
+            out.entry(s.op).or_insert_with(|| Op::new("TJ", vec![Object::Array(vec![pdfcraft_content::num(adjustment)])]));
+        }
+    }
+    out
+}
+
+/// For each operator: whether a run shown after it in its text object, and not in `drop`, is
+/// placed by the pen it left rather than by a line move of its own (see [`dropped_advances`]).
+/// A `Q` puts back the text matrices its `q` saved (as [`interpret`] reads it), so a line move
+/// between them doesn't count for the text after the `Q`. Leaving an advance in is harmless where
+/// nothing turns out to use it. One pass from the end, so a page of many dropped runs stays linear.
+fn kept_run_follows(ops: &[Op], drop: &std::collections::HashSet<usize>) -> Vec<bool> {
+    // The `q` and `Q` that pair up: [`interpret`] ignores a `Q` with nothing saved, so only a
+    // `Q` that restores something is a boundary here.
+    let mut paired = vec![false; ops.len()];
+    let mut open: Vec<usize> = Vec::new();
+    for (i, op) in ops.iter().enumerate() {
+        if op.is("q") {
+            open.push(i);
+        } else if op.is("Q")
+            && let Some(q) = open.pop()
+        {
+            for at in [q, i] {
+                if let Some(slot) = paired.get_mut(at) {
+                    *slot = true;
+                }
+            }
+        }
+    }
+    let mut out = vec![false; ops.len()];
+    let mut follows = false;
+    // What followed each `Q` still open (read backwards), restored at its `q`.
+    let mut after_restore: Vec<bool> = Vec::new();
+    for (i, op) in ops.iter().enumerate().rev() {
+        if let Some(slot) = out.get_mut(i) {
+            *slot = follows;
+        }
+        let pairs = paired.get(i).copied().unwrap_or(false);
+        match op.op.as_slice() {
+            b"Q" if pairs => {
+                after_restore.push(follows);
+                follows = false;
+            }
+            b"q" if pairs => follows = follows || after_restore.pop().unwrap_or(false),
+            b"ET" | b"BT" | b"Td" | b"TD" | b"Tm" | b"T*" | b"'" | b"\"" => follows = false,
+            b"Tj" | b"TJ" if !drop.contains(&i) => follows = true,
+            _ => {}
+        }
+    }
+    out
+}
+
 /// The page's streams joined into the one stream they are: an operator may span two of them.
 pub(crate) fn joined(streams: &[ContentStream]) -> Pieces {
     Pieces::join(&streams.iter().map(|s| s.data.as_slice()).collect::<Vec<_>>())

crates/edit/src/text/rewrite.rs

@@ -4,7 +4,10 @@ use super::fallback::{
     source_encodes, source_family, source_program_completes, source_show, source_space, source_width, type3_encode, type3_font,
 };
 use super::interp::{Carry, Origin, TextState, interpret};
-use super::lines::{content_streams, joined, page_dict, rewritten_contents, splice, text_lines};
+use super::lines::{
+    content_streams, dropped_advances, dropped_side_effects, joined, page_dict, reopen_text_object, rewritten_contents, show_side_effects, splice,
+    text_lines,
+};
 use super::{
     Dict, Document, EditError, HashMap, Matrix, Metrics, Object, Op, PdfString, TextLine, TextSession, alignment_frame, group_blocks, is_centred,
     parse, rewrite_changed_words, rewrite_styled_block,
@@ -68,16 +71,8 @@ pub(crate) fn replace_line_with_limit(doc: &mut Document, page: usize, line: usi
     let reused = font.as_ref().filter(|m| source_encodes(m, &shown));
     let mut substituted = None;
     let mut replacement: Vec<Op> = Vec::new();
-    // ' and " also move to the next line; keep that.
-    match ops[first].op.as_slice() {
-        b"'" => replacement.push(Op::new("T*", vec![])),
-        b"\"" => {
-            replacement.push(Op::new("Tw", vec![ops[first].operands.first().cloned().unwrap_or(Object::Int(0))]));
-            replacement.push(Op::new("Tc", vec![ops[first].operands.get(1).cloned().unwrap_or(Object::Int(0))]));
-            replacement.push(Op::new("T*", vec![]));
-        }
-        _ => {}
-    }
+    // ' and " also move to the next line (and " sets the spacing); keep that.
+    replacement.extend(ops.get(first).map(show_side_effects).unwrap_or_default());
     match reused {
         Some(metrics) => replacement.extend(source_show(
             metrics,
@@ -134,8 +129,23 @@ pub(crate) fn replace_line_with_limit(doc: &mut Document, page: usize, line: usi
             }
         }
     }
-    // Rebuild: the line's first operator becomes the replacement, its others go.
-    let new_data = splice(&pieces, &ops, |i| if i == first { (std::mem::take(&mut replacement), false) } else { (Vec::new(), !drops.contains(&i)) });
+    // Rebuild: the line's first operator becomes the replacement, its others go. Each other
+    // dropped `'` or `"` (a later run, or a copy on the same baseline) leaves its line move and
+    // spacing behind, as the first one does inside the replacement, and a dropped copy its advance
+    // where text after it is placed by that (the line's own runs give way to the replacement's).
+    let mut advances = dropped_advances(doc, &ops, &res, &drops);
+    for i in &target.ops {
+        advances.remove(i);
+    }
+    let new_data = splice(&pieces, &ops, |i| {
+        if i == first {
+            return (std::mem::take(&mut replacement), false);
+        }
+        let keep = !drops.contains(&i);
+        let mut insert = dropped_side_effects(&ops, i, keep, None);
+        insert.extend(advances.remove(&i));
+        (insert, keep)
+    });
     let contents = rewritten_contents(doc, &streams, new_data)?;
     let page_ref = p.obj;
     if substituted.is_some() {
@@ -995,16 +1005,18 @@ pub(crate) fn rewrite_block_from(
     };
     let mut block_ops = block_ops(&plan, &writer, &wrapped, font.show_font.clone())?;
     let on_top = crate::lift_on_top(over, &mut block_ops);
-    let n = pdfcraft_content::num;
     block_ops.extend(after.ops().into_iter().filter(|op| !op.is("Tf") || after.font.is_some()));
     if split {
         block_ops.insert(0, Op::new("ET", vec![]));
-        block_ops.push(Op::new("BT", vec![]));
-        block_ops.push(Op::new("Tm", emit.tlm.iter().map(|v| n(*v)).collect()));
+        block_ops.extend(reopen_text_object(emit.tlm, emit.tm, after.font.as_ref().map(|(_, size)| *size), after.scale));
     }
+    let mut advances = dropped_advances(doc, &ops, &res, &dropped);
     let new_data = splice(&pieces, &ops, |i| {
-        let insert = if i == at { std::mem::take(&mut block_ops) } else { Vec::new() };
-        (insert, !dropped.contains(&i))
+        let mut insert = if i == at { std::mem::take(&mut block_ops) } else { Vec::new() };
+        let keep = !dropped.contains(&i);
+        insert.extend(dropped_side_effects(&ops, i, keep, split.then_some(start)));
+        insert.extend(advances.remove(&i));
+        (insert, keep)
     });
     let contents = rewritten_contents(doc, &streams, new_data)?;
     let new_font = !reuse;

crates/edit/src/text_regions/ocr_words.rs

@@ -150,8 +150,8 @@ fn key(line: &TextLine) -> (&str, [i64; 4]) {
 }
 
 /// How far right a rewrite of the runs `indices` drew (`None` when it drew nothing), or an error
-/// when it moved or lost any other text on the page: text positioned after the end of the text
-/// before it, say, depends on the words that went.
+/// when it moved or lost any other text on the page: text positioned after the end of the words
+/// that went, say, when their advance couldn't be left behind (see `dropped_advances`).
 fn drawn_right(before: &[TextLine], indices: &[usize], after: &[TextLine]) -> Result<Option<f64>, EditError> {
     let mut unmatched: HashMap<_, usize> = HashMap::new();
     for line in before {

crates/edit/src/text_regions/styled.rs

@@ -1546,7 +1546,8 @@ fn push_row_break_marker(block_ops: &mut Vec<Op>, row_soft: &[bool], row_gap: &[
 /// [`splice`] with the rewritten rows spliced in at `at`, and (when `marker` names one) a `/P`
 /// marker opened at its start and closed at its `next` line or, when nothing follows, after the
 /// paragraph's own last `ET` (appended past the stream's last operator when that close is at or
-/// beyond `ops.len()`, since `splice`'s callback never visits that index).
+/// beyond `ops.len()`, since `splice`'s callback never visits that index). A dropped operator
+/// `i` leaves `left_behind(i, keep)` in its place: its line move, spacing and advance.
 fn splice_with_marker(
     pieces: &Pieces,
     ops: &[Op],
@@ -1554,6 +1555,7 @@ fn splice_with_marker(
     at: usize,
     mut block_ops: Vec<Op>,
     drop: &std::collections::HashSet<usize>,
+    mut left_behind: impl FnMut(usize, bool) -> Vec<Op>,
 ) -> Vec<Vec<u8>> {
     let data = splice(pieces, ops, |i| {
         let mut insert = Vec::new();
@@ -1571,7 +1573,9 @@ fn splice_with_marker(
         if i == at {
             insert.append(&mut block_ops);
         }
-        (insert, !drop.contains(&i))
+        let keep = !drop.contains(&i);
+        insert.extend(left_behind(i, keep));
+        (insert, keep)
     });
     if !marker.is_some_and(|(_, next, close)| next.is_none() && close >= ops.len()) {
         return data;
@@ -1896,14 +1900,21 @@ pub(crate) fn rewrite_styled_block(
     block_ops.extend(after.ops());
     if split {
         block_ops.insert(0, Op::new("ET", vec![]));
-        block_ops.push(Op::new("BT", vec![]));
-        block_ops.push(Op::new("Tm", o.tlm.iter().map(|v| n(*v)).collect()));
+        block_ops.extend(crate::text::reopen_text_object(o.tlm, o.tm, after.font.as_ref().map(|(_, size)| *size), after.scale));
     }
     // A kept source row sits outside `block_ops`. Bound the whole paragraph when a marker is
     // safe. The close is not part of `block_ops`: that vector can end inside a text object
     // when the rewrite splits one, and a kept row's operators come later in the stream.
     let marker = if marked { None } else { paragraph_marker(block, lines, &ops) };
-    let data = splice_with_marker(&pieces, &ops, marker, at, block_ops, &drop);
+    // A dropped `'` or `"` leaves its line move and spacing, and a dropped show its advance.
+    let mut advances = crate::text::dropped_advances(doc, &ops, &res, &drop);
+    let split_at = split.then_some(start);
+    let left_behind = |i: usize, keep: bool| {
+        let mut out = crate::text::dropped_side_effects(&ops, i, keep, split_at);
+        out.extend(advances.remove(&i));
+        out
+    };
+    let data = splice_with_marker(&pieces, &ops, marker, at, block_ops, &drop, left_behind);
     let contents = rewritten_contents(doc, &streams, data)?;
     res.set(b"Font".to_vec(), Object::Dict(fonts));
     doc.update_dict(p.obj, |d| {

crates/engine/tests/it/ocr_edit.rs

@@ -419,18 +419,21 @@ fn a_formatting_change_redraws_the_whole_ocr_phrase() {
     assert_eq!(drawn.join(" "), "John Smyth Example");
 }
 
-/// A layer whose words follow one another with no position of their own: a word that went would
-/// move those after it, so keeping them isn't possible and the whole phrase is redrawn instead.
+/// A layer whose words follow one another with no position of their own: a word that goes leaves
+/// its advance behind (ISO 32000-2 §9.4.4), so the words after it stay where they were and are
+/// kept as the scan, with nothing drawn.
 #[test]
-fn words_that_depend_on_the_one_before_are_redrawn_rather_than_moved() {
+fn words_that_depend_on_the_one_before_are_kept_in_place() {
     let bytes = under_scan("BT /F1 10 Tf 3 Tr 20 44 Td (John) Tj ( ) Tj (Smith) Tj ( ) Tj (Example) Tj ET");
     let mut s = Session::new();
     let id = s.open("relative.pdf", None, bytes, None).unwrap();
     assert_eq!(texts(&s, id), ["John Smith Example"]);
+    let right = |s: &Session| s.get(id).unwrap().text_lines(0).iter().find(|l| l.text.contains("Example")).map(|l| l.rect[2]);
+    let before = right(&s).unwrap();
     edit_block(&mut s, id, 0, "John Example");
     let (scan, drawn) = scan_and_drawn(&s, id);
-    assert!(scan.is_empty(), "no word is left to shift under the scan: {scan:?}");
-    assert_eq!(drawn, ["John Example"]);
+    assert_eq!((scan, drawn), (vec!["John".to_owned(), "Example".to_owned()], Vec::<String>::new()));
+    assert_eq!(right(&s), Some(before), "Example stays where it was");
 }
 
 /// The edit survives a save and reopen, and each piece can be edited again.
@@ -460,19 +463,21 @@ fn a_draft_with_the_same_words_changes_nothing() {
     }
 }
 
-/// Visible text positioned after the end of an OCR word depends on that word. An edit may not
-/// leave the word gone and the visible text somewhere else while calling the rest kept.
+/// Visible text positioned after the end of an OCR word depends on that word. The word that goes
+/// leaves its advance behind, so the visible text stays where it was and the word kept stays the
+/// scan's.
 #[test]
-fn visible_text_that_follows_an_ocr_word_stops_it_being_kept_alone() {
+fn visible_text_that_follows_a_removed_ocr_word_stays_in_place() {
     let bytes = under_scan("BT /F1 10 Tf 3 Tr 20 44 Td (John) Tj ( ) Tj (Smith) Tj 0 Tr /F1 14 Tf ( Label) Tj ET");
     let mut s = Session::new();
     let id = s.open("label.pdf", None, bytes, None).unwrap();
     let label = |s: &Session| s.get(id).unwrap().text_lines(0).iter().find(|l| l.text.contains("Label")).map(|l| l.rect[0]);
-    assert_eq!(scan_and_drawn(&s, id).0, ["John Smith"]);
+    assert_eq!(scan_and_drawn(&s, id), (vec!["John Smith".to_owned()], vec!["Label".to_owned()]));
     let before = label(&s).unwrap();
     edit_block(&mut s, id, 0, "John");
-    let (scan, _) = scan_and_drawn(&s, id);
-    assert!(scan.is_empty(), "John can't stay alone when Label would move with it: {scan:?}, Label at {:?} from {before}", label(&s));
+    // Nothing new is drawn: the visible text is the page's own.
+    assert_eq!(scan_and_drawn(&s, id), (vec!["John".to_owned()], vec!["Label".to_owned()]));
+    assert_eq!(label(&s), Some(before), "Label stays where it was");
 }
 
 /// A large word right before a small one, as OCR's sizes can make them: the large word's cover,