From 5bbab0fa181329d01973c489bc6fb01b4f863ab4 Mon Sep 17 00:00:00 2001
From: "Dylan M. Taylor" <dylan@dylanmtaylor.com>
Date: Tue, 3 Nov 2026 04:23:05 +0000
Subject: [PATCH] fix(pdf): drop an oversized hyperlink before it is copied
 once per line

Every linked line copied the destination string, and its length was only
checked when the annotation was written, so one multi-megabyte link on text
wrapping onto many lines was copied that many times first. The length is
checked where the link areas are collected.
---
 crates/pdf/src/export_tests.rs | 17 +++++++++++++++++
 crates/pdf/src/text.rs         |  4 +++-
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/crates/pdf/src/export_tests.rs b/crates/pdf/src/export_tests.rs
index 259e58327..d41f11379 100644
--- a/crates/pdf/src/export_tests.rs
+++ b/crates/pdf/src/export_tests.rs
@@ -284,3 +284,20 @@ fn depth_samples() {
         std::fs::write(format!("{stem}-{name}.png"), figcraft_render::encode_png(&pix).unwrap()).unwrap();
     }
 }
+
+#[test]
+fn an_oversized_link_is_dropped_before_it_is_copied_per_line() {
+    // One link far past MAX_URL on text that wraps onto many lines: no annotation, and the
+    // destination is never copied once per line on the way to being refused.
+    let mut d = Document::new("long link");
+    let p = d.first_page().unwrap_or(NodeId(0));
+    let f = d.create(p, NodeKind::Frame, "F", 0.0, 0.0, 300.0, 4000.0).unwrap();
+    let words = "word ".repeat(2_000);
+    let mut td = TextData::new(words.trim_end());
+    td.style.font_size = 20.0;
+    td.style.link = Some("https://example.com/".to_string() + &"a".repeat(1 << 20));
+    let t = d.create(f, NodeKind::Text(td), "T", 10.0, 10.0, 280.0, 3980.0).unwrap();
+    d.get_mut(t).unwrap().fills = vec![Paint::solid(Color::BLACK)];
+    let pdf = export_pdf(&d, &[f], &PdfOptions::default()).unwrap();
+    assert_eq!(text(&pdf).matches("/Subtype/Link").count(), 0);
+}
diff --git a/crates/pdf/src/text.rs b/crates/pdf/src/text.rs
index abbb65b34..3b3917689 100644
--- a/crates/pdf/src/text.rs
+++ b/crates/pdf/src/text.rs
@@ -111,7 +111,9 @@ fn record_links(ex: &mut Exporter, layout: &TextLayout, gxf: Affine) {
         let glyphs = layout.glyphs.get(line.glyph_start..line.glyph_end).unwrap_or(&[]);
         for g in glyphs.iter().map(Some).chain([None]) {
             let link = g.and_then(|g| {
-                let url = layout.styles.get(g.style)?.link.as_deref().filter(|u| !u.trim().is_empty())?;
+                // Checked here, not when the annotation is written: every linked line copies
+                // the destination, so one oversized link must not be copied at all.
+                let url = layout.styles.get(g.style)?.link.as_deref().map(str::trim).filter(|u| !u.is_empty() && u.len() <= crate::MAX_URL)?;
                 let (a, b) = (g.x, g.x + g.advance);
                 (a.is_finite() && b.is_finite()).then(|| (url, a.min(b), a.max(b)))
             });