Fix overflow when adding delta

harfbuzz · Nov 9, 2024 · 26dfc0f · 26dfc0f
1 parent 34c0701
commit 26dfc0f
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Showing 4 changed files with 14 additions and 1 deletion.
diff --git a/src/hb/ot_layout_gsubgpos.rs b/src/hb/ot_layout_gsubgpos.rs
@@ -928,7 +928,7 @@ fn apply_lookup(
         //
         // It should be possible to construct tests for both of these cases.
 
-        end = (end as isize + delta) as _;
+        end = end.saturating_add_signed(delta);
         if end < match_positions[idx] {
             // End might end up being smaller than match_positions[idx] if the recursed
             // lookup ended up removing many items.

diff --git a/tests/custom/bugs.tests b/tests/custom/bugs.tests
@@ -1,2 +1,3 @@
 tests/fonts/rb_custom/NotoSansCJK.subset1.otf;--direction rtl;U+4F60,U+597D,U+FF0C;
 tests/fonts/rb_custom/OpenSans.subset1.ttf;--variations=wght=500,wdth=80;U+0065;
+tests/fonts/rb_custom/NotoSansMalayalam.subset1.ttf;;U+0D38,U+0D4D,U+0D25;
diff --git a/tests/fonts/rb_custom/NotoSansMalayalam.subset1.ttf b/tests/fonts/rb_custom/NotoSansMalayalam.subset1.ttf
diff --git a/tests/shaping/custom.rs b/tests/shaping/custom.rs
@@ -28,6 +28,18 @@ fn bugs_002() {
     );
 }
 
+#[test]
+fn bugs_003() {
+    assert_eq!(
+        shape(
+            "tests/fonts/rb_custom/NotoSansMalayalam.subset1.ttf",
+            "\u{0D38}\u{0D4D}\u{0D25}",
+            "",
+        ),
+        "gid7=0+1891"
+    );
+}
+
 #[test]
 fn fuzzer_001() {
     assert_eq!(