From 69c87d2f3e3353a204b09f91a8fc9198c3e1fdca Mon Sep 17 00:00:00 2001
From: aiongg <aiongtaigi@gmail.com>
Date: Thu, 22 Oct 2026 01:48:30 +0000
Subject: [PATCH] Integration: #3195 keep CMap entries read before a stream
 ends inside a block
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A begin… block cut off at the end of the stream returned None through ? and discarded the whole map; it now ends the scan like any other unparseable tail. Test: stream_cut_off_inside_a_block_keeps_the_entries_before_it.
---
 vendor/hayro-cmap/src/lib.rs   |  7 ++++++
 vendor/hayro-cmap/src/parse.rs | 41 ++++++++++++++++++++++++++--------
 2 files changed, 39 insertions(+), 9 deletions(-)

diff --git a/vendor/hayro-cmap/src/lib.rs b/vendor/hayro-cmap/src/lib.rs
index 4786e75e52..fb42ff37ec 100644
--- a/vendor/hayro-cmap/src/lib.rs
+++ b/vendor/hayro-cmap/src/lib.rs
@@ -1117,6 +1117,13 @@ endbfchar
         );
     }
 
+    #[test]
+    fn stream_cut_off_inside_a_block_keeps_the_entries_before_it() {
+        let cmap = parse_with_preamble(b"1 beginbfchar <41> <0058>\n<42> <00");
+        assert_eq!(cmap.lookup_bf_string(0x41), Some(BfString::Char('X')));
+        assert_eq!(cmap.lookup_bf_string(0x42), None);
+    }
+
     #[test]
     fn truncated_stream_with_no_entries_reports_failure() {
         // The tolerant parser keeps collected entries, but a stream that
diff --git a/vendor/hayro-cmap/src/parse.rs b/vendor/hayro-cmap/src/parse.rs
index 1137ab078d..a936209275 100644
--- a/vendor/hayro-cmap/src/parse.rs
+++ b/vendor/hayro-cmap/src/parse.rs
@@ -50,8 +50,10 @@ pub(crate) fn parse_inner<'a>(
     let mut last_name: Option<Vec<u8>> = None;
 
     // PdfCraft patch: track whether the scan was cut short. A CMap with an
-    // unparseable tail keeps the entries read so far instead of being
-    // discarded wholesale; one that yielded nothing still reports failure.
+    // unparseable tail, including one that ends inside a `begin…` block,
+    // keeps the entries read so far (the block parsers push into the shared
+    // lists as they go) instead of being discarded wholesale; one that
+    // yielded nothing still reports failure.
     let mut truncated = false;
 
     // PdfCraft patch: track a `usecmap` reference that could not be resolved
@@ -94,25 +96,46 @@ pub(crate) fn parse_inner<'a>(
         } else {
             match name.as_str() {
                 Some("begincodespacerange") => {
-                    parse_codespace_range(&mut scanner, &mut _codespace_ranges, &mut ctx)?;
+                    if parse_codespace_range(&mut scanner, &mut _codespace_ranges, &mut ctx).is_none() {
+                        truncated = true;
+                        break;
+                    }
                 }
                 Some("begincidrange") => {
-                    parse_range(&mut scanner, &mut ranges, &mut ctx, "endcidrange")?;
+                    if parse_range(&mut scanner, &mut ranges, &mut ctx, "endcidrange").is_none() {
+                        truncated = true;
+                        break;
+                    }
                 }
                 Some("begincidchar") => {
-                    parse_char(&mut scanner, &mut ranges, &mut ctx, "endcidchar")?;
+                    if parse_char(&mut scanner, &mut ranges, &mut ctx, "endcidchar").is_none() {
+                        truncated = true;
+                        break;
+                    }
                 }
                 Some("beginnotdefrange") => {
-                    parse_range(&mut scanner, &mut notdef_ranges, &mut ctx, "endnotdefrange")?;
+                    if parse_range(&mut scanner, &mut notdef_ranges, &mut ctx, "endnotdefrange").is_none() {
+                        truncated = true;
+                        break;
+                    }
                 }
                 Some("beginnotdefchar") => {
-                    parse_char(&mut scanner, &mut notdef_ranges, &mut ctx, "endnotdefchar")?;
+                    if parse_char(&mut scanner, &mut notdef_ranges, &mut ctx, "endnotdefchar").is_none() {
+                        truncated = true;
+                        break;
+                    }
                 }
                 Some("beginbfchar") => {
-                    parse_bf_char(&mut scanner, &mut bf_entries, &mut ctx)?;
+                    if parse_bf_char(&mut scanner, &mut bf_entries, &mut ctx).is_none() {
+                        truncated = true;
+                        break;
+                    }
                 }
                 Some("beginbfrange") => {
-                    parse_bf_range(&mut scanner, &mut bf_entries, &mut ctx)?;
+                    if parse_bf_range(&mut scanner, &mut bf_entries, &mut ctx).is_none() {
+                        truncated = true;
+                        break;
+                    }
                 }
                 Some("usecmap") => {
                     // PdfCraft patch: an unresolvable or unparseable `usecmap`