[GPOS] Disable split-kerning

harfbuzz/harfbuzz@88798ee8b

Author: LaurenzV

src/ot/position.rs

@@ -237,84 +237,7 @@ impl Apply for PairAdjustment<'_> {
                 let flags = matrix.value_format_flags();
                 let len2 = flags.1.len();
 
-                // Isolate simple kerning and apply it half to each side.
-                // Results in better cursor positioning / underline drawing.
-                if len2 == 0 {
-                    let dir = ctx.buffer.direction;
-                    let mut mask = if dir.is_horizontal() {
-                        ValueFormatFlags::x_advance()
-                    } else {
-                        ValueFormatFlags::y_advance()
-                    };
-
-                    if dir.is_backward() {
-                        mask |= mask >> 2;
-                    }
-
-                    mask |= mask << 4;
-
-                    if (flags.0.bits() & !mask) == 1 {
-                        return bail(ctx, records, len2);
-                    } else {
-                        let mut dummy_pos = GlyphPosition::default();
-                        if records.0.apply_to_pos(ctx, &mut dummy_pos) {
-                            let src = &mut dummy_pos;
-                            let (arr1, arr2) = ctx.buffer.pos.split_at_mut(second_glyph_index);
-                            let dst1 = &mut arr1[first_glyph_index];
-                            let dst2 = &mut arr2[0];
-
-                            let (
-                                src_advance,
-                                dst1_advance,
-                                dst2_advance,
-                                src_offset,
-                                dst1_offset,
-                                dst2_offset,
-                            ) = if dir.is_horizontal() {
-                                (
-                                    &mut src.x_advance,
-                                    &mut dst1.x_advance,
-                                    &mut dst2.x_advance,
-                                    &mut src.x_offset,
-                                    &mut dst1.x_offset,
-                                    &mut dst2.x_offset,
-                                )
-                            } else {
-                                (
-                                    &mut src.y_advance,
-                                    &mut dst1.y_advance,
-                                    &mut dst2.y_advance,
-                                    &mut src.y_offset,
-                                    &mut dst1.y_offset,
-                                    &mut dst2.y_offset,
-                                )
-                            };
-
-                            let kern = *src_advance;
-                            let kern1 = kern >> 1;
-                            let kern2 = kern - kern1;
-
-                            if !dir.is_backward() {
-                                *dst1_advance += kern1;
-                                *dst2_advance += kern2;
-                                *dst2_offset += kern2;
-                            } else {
-                                *dst1_advance += kern1;
-                                *dst1_offset += *src_offset - kern2;
-                                *dst2_advance += kern2;
-                            }
-
-                            let applied_first = kern != 0;
-                            let applied_second = kern != 0;
-
-                            return success(ctx, applied_first, applied_second, len2);
-                        } else {
-                            return boring(ctx, len2);
-                        }
-                    }
-                } else {
-                    return bail(ctx, records, len2);
-                }
+                return bail(ctx, records, len2);
             }
         };
 

tests/shaping/aots.rs

@@ -696,6 +696,21 @@ fn gpos2_2_004() {
     );
 }
 
+#[test]
+fn gpos2_2_005() {
+    assert_eq!(
+        shape(
+            "tests/fonts/aots/gpos2_2_font5.otf",
+            "\u{0012}\u{0012}\u{0012}\u{0012}",
+            "--features=\"test\" --single-par --no-clusters --no-glyph-names --ned",
+        ),
+        "18@-100,0|\
+         18@1400,0|\
+         18@2900,0|\
+         18@4500,0"
+    );
+}
+
 #[test]
 fn gpos3_002() {
     assert_eq!(

tests/shaping/in_house.rs

@@ -7481,8 +7481,8 @@ fn positioning_features_001() {
             "\u{0041}\u{0056}",
             "",
         ),
-        "A=0+665|\
-         V=1@-40,0+635"
+        "A=0+625|\
+         V=1+675"
     );
 }