[pango] Update pango_default_break function for Word Boundary

[Matthias Clasen <matthiasc src gnome org>]

commit 238ac31bd8cc1ef32f18317328381155093ded07
Author: Peng Wu <alexepico gmail com>
Date:   Thu Jun 15 15:35:35 2017 +0800

    Update pango_default_break function for Word Boundary
    
    Improve Word Boundary Rule for Hebrew_Letter, Single_Quote,
    Double_Quote and Regional Indicator.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=782813

 pango/break.c |   75 ++++++++++++++++++++++++++++++++++++++++++++------------
 1 files changed, 59 insertions(+), 16 deletions(-)
---
diff --git a/pango/break.c b/pango/break.c
index b650ca5..5b2128d 100644
--- a/pango/break.c
+++ b/pango/break.c
@@ -540,12 +540,15 @@ pango_default_break (const gchar   *text,
     WB_NewlineCRLF,
     WB_ExtendFormat,
     WB_Katakana,
+    WB_Hebrew_Letter,
     WB_ALetter,
     WB_MidNumLet,
     WB_MidLetter,
     WB_MidNum,
     WB_Numeric,
     WB_ExtendNumLet,
+    WB_RI_Odd,
+    WB_RI_Even,
   } WordBreakType;
   WordBreakType prev_prev_WB_type = WB_Other, prev_WB_type = WB_Other;
   gint prev_WB_i = -1;
@@ -863,7 +866,8 @@ pango_default_break (const gchar   *text,
       /* ---- UAX#29 Word Boundaries ---- */
       {
        is_word_boundary = FALSE;
-       if (is_grapheme_boundary) /* Rules WB3 and WB4 */
+       if (is_grapheme_boundary ||
+           G_UNLIKELY(wc >=0x1F1E6 && wc <=0x1F1FF)) /* Rules WB3 and WB4 */
          {
            PangoScript script;
            WordBreakType WB_type;
@@ -876,6 +880,9 @@ pango_default_break (const gchar   *text,
            if (script == PANGO_SCRIPT_KATAKANA)
              WB_type = WB_Katakana;
 
+           if (script == PANGO_SCRIPT_HEBREW && type == G_UNICODE_OTHER_LETTER)
+             WB_type = WB_Hebrew_Letter;
+
            if (WB_type == WB_Other)
              switch (wc >> 8)
                {
@@ -952,6 +959,17 @@ pango_default_break (const gchar   *text,
                case G_UNICODE_OTHER_SYMBOL:
                  if (wc >= 0x24B6 && wc <= 0x24E9) /* Other_Alphabetic */
                    goto Alphabetic;
+
+                 if (G_UNLIKELY(wc >=0x1F1E6 && wc <=0x1F1FF))
+                   {
+                         if (prev_WB_type == WB_RI_Odd)
+                          WB_type = WB_RI_Even;
+                         else if (prev_WB_type == WB_RI_Even)
+                          WB_type = WB_RI_Odd;
+                         else
+                          WB_type = WB_RI_Odd;
+                   }
+
                  break;
 
                case G_UNICODE_OTHER_LETTER:
@@ -998,31 +1016,56 @@ pango_default_break (const gchar   *text,
            else if (WB_type == WB_ExtendFormat)
              is_word_boundary = FALSE; /* Rules WB4? */
            else if ((prev_WB_type == WB_ALetter  ||
-                     prev_WB_type == WB_Numeric  ||
-                     prev_WB_type == WB_ExtendNumLet) &&
-                    (     WB_type == WB_ALetter  ||
-                          WB_type == WB_Numeric  ||
-                          WB_type == WB_ExtendNumLet))
-             is_word_boundary = FALSE; /* Rules WB5, WB8, WB9, WB10, WB13a, WB13b */
-           else if ((prev_WB_type == WB_Katakana ||
-                     prev_WB_type == WB_ExtendNumLet) &&
-                    (     WB_type == WB_Katakana ||
-                          WB_type == WB_ExtendNumLet))
-             is_word_boundary = FALSE; /* Rules WB13, WB13a, WB13b */
-           else if ((prev_prev_WB_type == WB_ALetter && WB_type == WB_ALetter) &&
-                    (prev_WB_type == WB_MidLetter || prev_WB_type == WB_MidNumLet))
+                  prev_WB_type == WB_Hebrew_Letter ||
+                  prev_WB_type == WB_Numeric) &&
+                 (WB_type == WB_ALetter  ||
+                  WB_type == WB_Hebrew_Letter ||
+                  WB_type == WB_Numeric))
+             is_word_boundary = FALSE; /* Rules WB5, WB8, WB9, WB10 */
+           else if (prev_WB_type == WB_Katakana && WB_type == WB_Katakana)
+             is_word_boundary = FALSE; /* Rule WB13 */
+           else if ((prev_WB_type == WB_ALetter ||
+                  prev_WB_type == WB_Hebrew_Letter ||
+                  prev_WB_type == WB_Numeric ||
+                  prev_WB_type == WB_Katakana ||
+                  prev_WB_type == WB_ExtendNumLet) &&
+                 WB_type == WB_ExtendNumLet)
+             is_word_boundary = FALSE; /* Rule WB13a */
+           else if (prev_WB_type == WB_ExtendNumLet &&
+                 (WB_type == WB_ALetter ||
+                  WB_type == WB_Hebrew_Letter ||
+                  WB_type == WB_Numeric ||
+                  WB_type == WB_Katakana))
+             is_word_boundary = FALSE; /* Rule WB13b */
+           else if (((prev_prev_WB_type == WB_ALetter ||
+                   prev_prev_WB_type == WB_Hebrew_Letter) &&
+                  (WB_type == WB_ALetter ||
+                   WB_type == WB_Hebrew_Letter)) &&
+                    (prev_WB_type == WB_MidLetter ||
+              prev_WB_type == WB_MidNumLet ||
+              prev_wc == 0x0027))
              {
                attrs[prev_WB_i].is_word_boundary = FALSE; /* Rule WB6 */
                is_word_boundary = FALSE; /* Rule WB7 */
              }
+           else if (prev_WB_type == WB_Hebrew_Letter && wc == 0x0027)
+          is_word_boundary = FALSE; /* Rule WB7a */
+           else if (prev_prev_WB_type == WB_Hebrew_Letter && prev_wc == 0x0022 &&
+                 WB_type == WB_Hebrew_Letter) {
+          attrs[prev_WB_i].is_word_boundary = FALSE; /* Rule WB7b */
+          is_word_boundary = FALSE; /* Rule WB7c */
+        }
            else if ((prev_prev_WB_type == WB_Numeric && WB_type == WB_Numeric) &&
-                    (prev_WB_type == WB_MidNum || prev_WB_type == WB_MidNumLet))
+                 (prev_WB_type == WB_MidNum || prev_WB_type == WB_MidNumLet ||
+                  prev_wc == 0x0027))
              {
                is_word_boundary = FALSE; /* Rule WB11 */
                attrs[prev_WB_i].is_word_boundary = FALSE; /* Rule WB12 */
              }
+           else if (prev_WB_type == WB_RI_Odd && WB_type == WB_RI_Even)
+             is_word_boundary = FALSE; /* Rule WB15 and WB16 */
            else
-             is_word_boundary = TRUE; /* Rule WB14 */
+             is_word_boundary = TRUE; /* Rule WB999 */
 
            if (WB_type != WB_ExtendFormat)
              {