Fixes https://github.com/harfbuzz/harfbuzz/issues/1019
New numbers:
BENGALI: 353725 out of 354188 tests passed. 463 failed (0.130722%)
DEVANAGARI: 707261 out of 707394 tests passed. 133 failed (0.0188014%)
GUJARATI: 366353 out of 366457 tests passed. 104 failed (0.0283799%)
GURMUKHI: 60729 out of 60747 tests passed. 18 failed (0.0296311%)
KANNADA: 951300 out of 951913 tests passed. 613 failed (0.0643966%)
MALAYALAM: 1048136 out of 1048334 tests passed. 198 failed (0.0188871%)
ORIYA: 42327 out of 42329 tests passed. 2 failed (0.00472489%)
SINHALA: 271596 out of 271847 tests passed. 251 failed (0.0923313%)
TAMIL: 1091754 out of 1091754 tests passed. 0 failed (0%)
TELUGU: 970555 out of 970573 tests passed. 18 failed (0.00185457%)
Devanagari regressed because Uniscribe doesn't enforce the full set.
Tests added with the *-vowel-letters.txt files in tree and Noto fonts.
Note that there's minor positioning differences, and ONE reordering
difference between what we get for these and what Uniscribe gets.
Probably same as what's described in commit message for
1a96cc825d
From the new code (first paragraph is from the OT Devanagari spec.):
/* o Reorder matras:
*
* If a pre-base matra character had been reordered before applying basic
* features, the glyph can be moved closer to the main consonant based on
* whether half-forms had been formed. Actual position for the matra is
* defined as “after last standalone halant glyph, after initial matra
* position and before the main consonant”. If ZWJ or ZWNJ follow this
* halant, position is moved after it.
*
* IMPLEMENTATION NOTES:
*
* It looks like the last sentence is wrong. Testing, with Windows 7 Uniscribe
* and Devanagari shows that the behavior is best described as:
*
* "If ZWJ follows this halant, matra is NOT repositioned after this halant.
* If ZWNJ follows this halant, position is moved after it."
*
* Test case, with Adobe Devanagari or Nirmala UI:
*
* U+091F,U+094D,U+200C,U+092F,U+093F
* (Matra moves to the middle, after ZWNJ.)
*
* U+091F,U+094D,U+200D,U+092F,U+093F
* (Matra does NOT move, stays to the left.)
Fixes https://github.com/harfbuzz/harfbuzz/issues/1070
Test case added with Adobe Devanagari.
Behdad Esfahbod
Ebrahim Byagowi
David Corbett
Rod Sheeter