From 61f41849af6ff9edf8b55cf9610066d1bfb4a8df Mon Sep 17 00:00:00 2001
From: Behdad Esfahbod <behdad@behdad.org>
Date: Tue, 7 Aug 2012 16:45:27 -0400
Subject: [PATCH] Add Hebrew presentation forms shaping

Lifted from https://bugzilla.mozilla.org/show_bug.cgi?id=728866
---
 src/hb-unicode-private.hh | 121 +++++++++++++++++++++++++++++++++++++-
 1 file changed, 120 insertions(+), 1 deletion(-)

diff --git a/src/hb-unicode-private.hh b/src/hb-unicode-private.hh
index 5c5fff974..2a67f0a14 100644
--- a/src/hb-unicode-private.hh
+++ b/src/hb-unicode-private.hh
@@ -80,6 +80,7 @@ HB_UNICODE_FUNCS_IMPLEMENT_CALLBACKS_SIMPLE
 			    hb_codepoint_t *ab)
   {
     *ab = 0;
+
     /* XXX, this belongs to indic normalizer. */
     if ((FLAG (general_category (a)) &
 	 (FLAG (HB_UNICODE_GENERAL_CATEGORY_SPACING_MARK) |
@@ -88,7 +89,125 @@ HB_UNICODE_FUNCS_IMPLEMENT_CALLBACKS_SIMPLE
       return false;
     /* XXX, add composition-exclusion exceptions to Indic shaper. */
     if (a == 0x09AF && b == 0x09BC) { *ab = 0x09DF; return true; }
-    return func.compose (this, a, b, ab, user_data.compose);
+
+    /* XXX, these belong to the hebew / default shaper. */
+    /* Hebrew presentation-form shaping.
+     * https://bugzilla.mozilla.org/show_bug.cgi?id=728866 */
+    // Hebrew presentation forms with dagesh, for characters 0x05D0..0x05EA;
+    // note that some letters do not have a dagesh presForm encoded
+    static const hb_codepoint_t sDageshForms[0x05EA - 0x05D0 + 1] = {
+      0xFB30, // ALEF
+      0xFB31, // BET
+      0xFB32, // GIMEL
+      0xFB33, // DALET
+      0xFB34, // HE
+      0xFB35, // VAV
+      0xFB36, // ZAYIN
+      0, // HET
+      0xFB38, // TET
+      0xFB39, // YOD
+      0xFB3A, // FINAL KAF
+      0xFB3B, // KAF
+      0xFB3C, // LAMED
+      0, // FINAL MEM
+      0xFB3E, // MEM
+      0, // FINAL NUN
+      0xFB40, // NUN
+      0xFB41, // SAMEKH
+      0, // AYIN
+      0xFB43, // FINAL PE
+      0xFB44, // PE
+      0, // FINAL TSADI
+      0xFB46, // TSADI
+      0xFB47, // QOF
+      0xFB48, // RESH
+      0xFB49, // SHIN
+      0xFB4A // TAV
+    };
+
+    hb_bool_t found = func.compose (this, a, b, ab, user_data.compose);
+
+    if (!found && (b & ~0x7F) == 0x0580) {
+	// special-case Hebrew presentation forms that are excluded from
+	// standard normalization, but wanted for old fonts
+	switch (b) {
+	case 0x05B4: // HIRIQ
+	    if (a == 0x05D9) { // YOD
+		*ab = 0xFB1D;
+		found = true;
+	    }
+	    break;
+	case 0x05B7: // patah
+	    if (a == 0x05F2) { // YIDDISH YOD YOD
+		*ab = 0xFB1F;
+		found = true;
+	    } else if (a == 0x05D0) { // ALEF
+		*ab = 0xFB2E;
+		found = true;
+	    }
+	    break;
+	case 0x05B8: // QAMATS
+	    if (a == 0x05D0) { // ALEF
+		*ab = 0xFB2F;
+		found = true;
+	    }
+	    break;
+	case 0x05B9: // HOLAM
+	    if (a == 0x05D5) { // VAV
+		*ab = 0xFB4B;
+		found = true;
+	    }
+	    break;
+	case 0x05BC: // DAGESH
+	    if (a >= 0x05D0 && a <= 0x05EA) {
+		*ab = sDageshForms[a - 0x05D0];
+		found = (*ab != 0);
+	    } else if (a == 0xFB2A) { // SHIN WITH SHIN DOT
+		*ab = 0xFB2C;
+		found = true;
+	    } else if (a == 0xFB2B) { // SHIN WITH SIN DOT
+		*ab = 0xFB2D;
+		found = true;
+	    }
+	    break;
+	case 0x05BF: // RAFE
+	    switch (a) {
+	    case 0x05D1: // BET
+		*ab = 0xFB4C;
+		found = true;
+		break;
+	    case 0x05DB: // KAF
+		*ab = 0xFB4D;
+		found = true;
+		break;
+	    case 0x05E4: // PE
+		*ab = 0xFB4E;
+		found = true;
+		break;
+	    }
+	    break;
+	case 0x05C1: // SHIN DOT
+	    if (a == 0x05E9) { // SHIN
+		*ab = 0xFB2A;
+		found = true;
+	    } else if (a == 0xFB49) { // SHIN WITH DAGESH
+		*ab = 0xFB2C;
+		found = true;
+	    }
+	    break;
+	case 0x05C2: // SIN DOT
+	    if (a == 0x05E9) { // SHIN
+		*ab = 0xFB2B;
+		found = true;
+	    } else if (a == 0xFB49) { // SHIN WITH DAGESH
+		*ab = 0xFB2D;
+		found = true;
+	    }
+	    break;
+	}
+    }
+
+    return found;
   }
 
   inline hb_bool_t decompose (hb_codepoint_t ab,