Rewrite LRI/RLI/FSI handling in bidi_resolve_explicit_1.

1 files changed, 69 insertions, 55 deletions

diff --git a/src/bidi.c b/src/bidi.c
index 3c204a82b78..8d26dde4cf2 100644
--- a/src/bidi.c
+++ b/src/bidi.c
@@ -1836,59 +1836,6 @@ bidi_resolve_explicit_1 (struct bidi_it *bidi_it)
                      && bidi_it->next_en_type == WEAK_EN))
           type = WEAK_EN;
         break;
-      case FSI: /* X5c */
-        end = string_p ? bidi_it->string.schars : ZV;
-        disp_pos = bidi_it->disp_pos;
-        disp_prop = bidi_it->disp_prop;
-        nchars = bidi_it->nchars;
-        ch_len = bidi_it->ch_len;
-        typ1 = find_first_strong_char (bidi_it->charpos, bidi_it->bytepos, end,
-                                       &disp_pos, &disp_prop, &bidi_it->string,
-                                       bidi_it->w, string_p, bidi_it->frame_window_p,
-                                       &ch_len, &nchars, true);
-        if (typ1 != STRONG_R && typ1 != STRONG_AL)
-          {
-            type = LRI;
-            goto fsi_as_lri;
-          }
-        else
-          type = RLI;
-        /* FALLTHROUGH */
-      case RLI: /* X5a */
-        if (override == NEUTRAL_DIR)
-          bidi_it->type_after_w1 = type;
-        else    /* Unicode 8.0 correction.  */
-          bidi_it->type_after_w1 = (override == L2R ? STRONG_L : STRONG_R);
-        bidi_check_type (bidi_it->type_after_w1);
-        if (current_level < BIDI_MAXDEPTH
-            && bidi_it->invalid_levels == 0
-            && bidi_it->invalid_isolates == 0)
-          {
-            new_level = ((current_level + 1) & ~1) + 1;
-            bidi_it->isolate_level++;
-            bidi_push_embedding_level (bidi_it, new_level, NEUTRAL_DIR, true);
-          }
-        else
-          bidi_it->invalid_isolates++;
-        break;
-      case LRI: /* X5b */
-    fsi_as_lri:
-        if (override == NEUTRAL_DIR)
-          bidi_it->type_after_w1 = type;
-        else    /* Unicode 8.0 correction.  */
-          bidi_it->type_after_w1 = (override == L2R ? STRONG_L : STRONG_R);
-        bidi_check_type (bidi_it->type_after_w1);
-        if (current_level < BIDI_MAXDEPTH - 1
-            && bidi_it->invalid_levels == 0
-            && bidi_it->invalid_isolates == 0)
-          {
-            new_level = ((current_level + 2) & ~1);
-            bidi_it->isolate_level++;
-            bidi_push_embedding_level (bidi_it, new_level, NEUTRAL_DIR, true);
-          }
-        else
-          bidi_it->invalid_isolates++;
-        break;
       case PDI: /* X6a */
         if (bidi_it->invalid_isolates)
           {
@@ -1933,8 +1880,74 @@ bidi_resolve_explicit_1 (struct bidi_it *bidi_it)
           type = WEAK_EN;
         break;
       default:
-        /* Nothing.  */
-        break;
+        /* LRI, RLI, and FSI increment the embedding level of the
+           _following_ charcaters, so we must look at the type of the
+           previous character to support that.  */
+        switch (bidi_it->prev.orig_type)
+          {
+          case FSI:     /* X5c */
+            end = string_p ? bidi_it->string.schars : ZV;
+            disp_pos = bidi_it->disp_pos;
+            disp_prop = bidi_it->disp_prop;
+            nchars = bidi_it->nchars;
+            ch_len = bidi_it->ch_len;
+            typ1 = find_first_strong_char (bidi_it->charpos,
+                                           bidi_it->bytepos, end,
+                                           &disp_pos, &disp_prop,
+                                           &bidi_it->string, bidi_it->w,
+                                           string_p, bidi_it->frame_window_p,
+                                           &ch_len, &nchars, true);
+            if (typ1 != STRONG_R && typ1 != STRONG_AL)
+              {
+                type = LRI;
+                goto fsi_as_lri;
+              }
+            else
+              type = RLI;
+            /* FALLTHROUGH */
+          case RLI:     /* X5a */
+            eassert (bidi_it->prev.charpos == bidi_it->charpos - 1);
+            if (override == NEUTRAL_DIR)
+              bidi_it->type_after_w1 = type;
+            else        /* Unicode 8.0 correction.  */
+              bidi_it->type_after_w1 = (override == L2R ? STRONG_L : STRONG_R);
+            bidi_check_type (bidi_it->type_after_w1);
+            if (current_level < BIDI_MAXDEPTH
+                && bidi_it->invalid_levels == 0
+                && bidi_it->invalid_isolates == 0)
+              {
+                new_level = ((current_level + 1) & ~1) + 1;
+                bidi_it->isolate_level++;
+                bidi_push_embedding_level (bidi_it, new_level,
+                                           NEUTRAL_DIR, true);
+              }
+            else
+              bidi_it->invalid_isolates++;
+            break;
+          case LRI:     /* X5b */
+          fsi_as_lri:
+            eassert (bidi_it->prev.charpos == bidi_it->charpos - 1);
+            if (override == NEUTRAL_DIR)
+              bidi_it->type_after_w1 = type;
+            else        /* Unicode 8.0 correction.  */
+              bidi_it->type_after_w1 = (override == L2R ? STRONG_L : STRONG_R);
+            bidi_check_type (bidi_it->type_after_w1);
+            if (current_level < BIDI_MAXDEPTH - 1
+                && bidi_it->invalid_levels == 0
+                && bidi_it->invalid_isolates == 0)
+              {
+                new_level = ((current_level + 2) & ~1);
+                bidi_it->isolate_level++;
+                bidi_push_embedding_level (bidi_it, new_level,
+                                           NEUTRAL_DIR, true);
+              }
+            else
+              bidi_it->invalid_isolates++;
+            break;
+          default:
+            /* Nothing.  */
+            break;
+          }
     }
 
   bidi_it->type = type;
@@ -1983,6 +1996,7 @@ bidi_resolve_explicit (struct bidi_it *bidi_it)
                                                        + bidi_it->ch_len, s,
                                                        bidi_it->string.unibyte)))
         {
+          bidi_remember_char (&bidi_it->prev, bidi_it);
           /* This advances to the next character, skipping any
              characters covered by display strings.  */
           level = bidi_resolve_explicit_1 (bidi_it);