Refuse header/footer Bates numbers that would overflow u64 (#2253)

Found while testing crates/edit/src/lib.rs:445

Co-authored-by: Claude Haiku 5.5 <noreply@anthropic.com>
Co-authored-by: Brandon Thomas <echelon@gmail.com>

contributors/people.toml

@@ -136,3 +136,7 @@ real_name = "Alexander Alber"
 [people.mtlcl410]
 display_name = "mtlcl410"
 sync_github_name = false
+
+[people.Silvertree2010]
+display_name = "Netter"
+sync_github_name = false

crates/edit/src/lib.rs

@@ -450,18 +450,26 @@ pub fn add_header_footer(doc: &mut Document, pages: &[usize], hf: &HeaderFooter,
             u32::MAX
         )));
     }
+    // The same goes for Bates numbers: the last selected page must still fit in a u64.
+    let bates0 = hf.text.iter().find_map(|t| bates_start(t)).unwrap_or(1);
+    if bates0.checked_add(pages.len().saturating_sub(1) as u64).is_none() {
+        return Err(EditError::Invalid(format!(
+            "the Bates start number {bates0} leaves no room for {} pages (Bates numbers stop at {})",
+            pages.len(),
+            u64::MAX
+        )));
+    }
     if replace {
         remove_marks(doc, pages, MarkKind::HeaderFooter)?;
     }
     let all = page_list(doc);
     let count = all.len();
-    let bates0 = hf.text.iter().find_map(|t| bates_start(t)).unwrap_or(1);
     for (k, &i) in pages.iter().enumerate() {
         let page = &all[i];
         let (w, h) = page.display_size(doc);
         let number =
             u32::try_from(u64::from(hf.start_number) + k as u64).map_err(|_| EditError::Invalid("the header page numbers are too large".into()))?;
-        let bates = bates0 + k as u64;
+        let bates = bates0.checked_add(k as u64).ok_or_else(|| EditError::Invalid("the Bates numbers are too large".into()))?;
         let size = hf.font_size;
         let [top, bottom, left, right] = hf.margins;
         let mut body: Vec<u8> = format!("BT\n/PCHelv {} Tf\n{}\n", n(size), rgb(hf.color)).into_bytes();

crates/edit/src/tests.rs

@@ -115,6 +115,23 @@ fn header_start_number_that_would_wrap_is_refused_without_drawing() {
     assert_eq!(marks_present(&doc).len(), 1);
 }
 
+#[test]
+fn header_bates_start_that_would_overflow_is_refused_without_drawing() {
+    // A Bates start of u64::MAX has no room for a second page. The run must be refused up front
+    // instead of overflowing (a panic in debug builds, a wrap to 0 in release builds).
+    let mut doc = fixture();
+    let hf = HeaderFooter {
+        text: [String::new(), String::new(), "<<Bates Number#6#18446744073709551615#A#B>>".into(), String::new(), String::new(), String::new()],
+        ..HeaderFooter::default()
+    };
+    let err = add_header_footer(&mut doc, &[0, 1], &hf, false, &cx()).unwrap_err();
+    assert!(err.to_string().contains("Bates"), "{err}");
+    assert!(marks_present(&doc).is_empty(), "nothing is drawn when the run is refused");
+    // A single page still fits the start number itself.
+    add_header_footer(&mut doc, &[0], &hf, false, &cx()).unwrap();
+    assert_eq!(marks_present(&doc).len(), 1);
+}
+
 #[test]
 fn replace_and_remove_restore_the_original_content() {
     let mut doc = fixture();