diff --git a/src/hb-ot-shape-complex-indic.cc b/src/hb-ot-shape-complex-indic.cc index 09742b391..a4f2d9a84 100644 --- a/src/hb-ot-shape-complex-indic.cc +++ b/src/hb-ot-shape-complex-indic.cc @@ -752,7 +752,28 @@ initial_reordering_consonant_syllable (const hb_ot_shape_plan_t *plan, * We could use buffer->sort() for this, if there was no special * reordering of pre-base stuff happening later... * We don't want to merge_clusters all of that, which buffer->sort() - * would. + * would. Here's a concrete example: + * + * Assume there's a pre-base consonant and explicit Halant before base, + * followed by a prebase-reordering (left) Matra: + * + * C,H,ZWNJ,B,M + * + * At this point in reordering we would have: + * + * M,C,H,ZWNJ,B + * + * whereas in final reordering we will bring the Matra closer to Base: + * + * C,H,ZWNJ,M,B + * + * That's why we don't want to merge-clusters anything before the Base + * at this point. But if something moved from after Base to before it, + * we should merge clusters from base to them. In final-reordering, we + * only move things around before base, and merge-clusters up to base. + * These two merge-clusters from the two sides of base will interlock + * to merge things correctly. See: + * https://github.com/harfbuzz/harfbuzz/issues/2272 */ if (indic_plan->is_old_spec || end - start > 127) buffer->merge_clusters (base, end); @@ -762,17 +783,18 @@ initial_reordering_consonant_syllable (const hb_ot_shape_plan_t *plan, for (unsigned int i = base; i < end; i++) if (info[i].syllable() != 255) { + unsigned int min = i; unsigned int max = i; unsigned int j = start + info[i].syllable(); while (j != i) { + min = hb_min (min, j); max = hb_max (max, j); unsigned int next = start + info[j].syllable(); info[j].syllable() = 255; /* So we don't process j later again. */ j = next; } - if (i != max) - buffer->merge_clusters (i, max + 1); + buffer->merge_clusters (hb_max (base, min), max + 1); } } diff --git a/test/shaping/data/in-house/fonts/6f36d056bad6d478fc0bf7397bd52dc3bd197d5f.ttf b/test/shaping/data/in-house/fonts/6f36d056bad6d478fc0bf7397bd52dc3bd197d5f.ttf new file mode 100644 index 000000000..395f42369 Binary files /dev/null and b/test/shaping/data/in-house/fonts/6f36d056bad6d478fc0bf7397bd52dc3bd197d5f.ttf differ diff --git a/test/shaping/data/in-house/tests/cluster.tests b/test/shaping/data/in-house/tests/cluster.tests index 928843f0f..f1889900b 100644 --- a/test/shaping/data/in-house/tests/cluster.tests +++ b/test/shaping/data/in-house/tests/cluster.tests @@ -1,2 +1,3 @@ ../fonts/4fac3929fc3332834e93673780ec0fe94342d193.ttf:--cluster-level=2:U+0078,U+030A,U+0058,U+030A:[gid2=0+1083|gid3=1@-1132,-8+0|gid1=2+1200|gid3=3@-1190,349+0] ../fonts/43ef465752be9af900745f72fe29cb853a1401a5.ttf:--cluster-level=1:U+05D4,U+05B7,U+05E9,U+05BC,U+05C1,U+05B8,U+05DE,U+05B4,U+05DD:[uni05DD=8+1359|uni05B4=7@111,0+0|uni05DE=6+1391|uni05B8=5+0|uni05BC=3+0|uni05C1=3+0|uni05E9=2+1451|uni05B7=1@28,0+0|uni05D4=0+1338] +../fonts/6f36d056bad6d478fc0bf7397bd52dc3bd197d5f.ttf:--cluster-level=1:U+099B,U+09CB,U+09C8,U+09C2,U+09CB,U+098C:[evowelsigninibeng=0+346|aivowelsignbeng=0+346|evowelsignbeng=0+346|chabeng=0+687|uuvowelsignlongbeng=0@-96,0+0|aavowelsignbeng=0+266|aavowelsignbeng=4+266|lvocalicbeng=5+639]