Fixed bidi_resolve_explicit_1 wrt isolate initiators and PDF.

bidi_resolve_neutral needs to be fixed, as it now aborts at line 2432.

1 files changed, 35 insertions, 20 deletions

diff --git a/src/bidi.c b/src/bidi.c
index 8d26dde4cf2..d928a00af30 100644
--- a/src/bidi.c
+++ b/src/bidi.c
@@ -1681,7 +1681,7 @@ static int
 bidi_resolve_explicit_1 (struct bidi_it *bidi_it)
 {
   int curchar;
-  bidi_type_t type, typ1;
+  bidi_type_t type, typ1, prev_type = UNKNOWN_BT;;
   int current_level;
   int new_level;
   bidi_dir_t override;
@@ -1719,6 +1719,17 @@ bidi_resolve_explicit_1 (struct bidi_it *bidi_it)
             }
           eassert (bidi_it->bytepos == CHAR_TO_BYTE (bidi_it->charpos));
         }
+      /* Determine the orginal bidi type of the previous character,
+         which is needed for handling isolate initiators and PDF.  The
+         type of the previous character will only be non-trivial if
+         our caller moved through some previous text in
+         get_visually_first_element, in which case bidi_it->prev holds
+         the information we want.  */
+      if (bidi_it->first_elt && bidi_it->prev.type != UNKNOWN_BT)
+        {
+          eassert (bidi_it->prev.charpos == bidi_it->charpos - 1);
+          prev_type = bidi_it->prev.orig_type;
+        }
     }
   /* Don't move at end of buffer/string.  */
   else if (bidi_it->charpos < (string_p ? bidi_it->string.schars : ZV))
@@ -1731,6 +1742,7 @@ bidi_resolve_explicit_1 (struct bidi_it *bidi_it)
       if (bidi_it->ch_len == 0)
         emacs_abort ();
       bidi_it->bytepos += bidi_it->ch_len;
+      prev_type = bidi_it->orig_type;
     }
 
   current_level = bidi_it->level_stack[bidi_it->stack_idx].level; /* X1 */
@@ -1864,26 +1876,18 @@ bidi_resolve_explicit_1 (struct bidi_it *bidi_it)
         bidi_it->type_after_w1 = type;
         bidi_check_type (bidi_it->type_after_w1);
         type = WEAK_BN; /* X9/Retaining */
-        if (bidi_it->ignore_bn_limit <= -1)
-          {
-            if (!bidi_it->invalid_isolates)
-              {
-                if (bidi_it->invalid_levels)
-                  bidi_it->invalid_levels--;
-                else if (!isolate_status && bidi_it->stack_idx > 1)
-                  bidi_pop_embedding_level (bidi_it);
-              }
-          }
-        else if (bidi_it->prev.type_after_w1 == WEAK_EN /* W5/Retaining */
-                 || (bidi_it->next_en_pos > bidi_it->charpos
-                     && bidi_it->next_en_type == WEAK_EN))
+        if (bidi_it->ignore_bn_limit > -1
+            && bidi_it->prev.type_after_w1 == WEAK_EN /* W5/Retaining */
+            || (bidi_it->next_en_pos > bidi_it->charpos
+                && bidi_it->next_en_type == WEAK_EN))
           type = WEAK_EN;
         break;
       default:
-        /* 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)
+        /* LRI, RLI, and FSI increment, and PDF decrements, the
+           embedding level of the _following_ characters, so we must
+           look at the type of the previous character to support
+           that.  */
+        switch (prev_type)
           {
           case FSI:     /* X5c */
             end = string_p ? bidi_it->string.schars : ZV;
@@ -1906,7 +1910,6 @@ bidi_resolve_explicit_1 (struct bidi_it *bidi_it)
               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.  */
@@ -1926,7 +1929,6 @@ bidi_resolve_explicit_1 (struct bidi_it *bidi_it)
             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.  */
@@ -1944,6 +1946,19 @@ bidi_resolve_explicit_1 (struct bidi_it *bidi_it)
             else
               bidi_it->invalid_isolates++;
             break;
+          case PDF:     /* X7 */
+            if (bidi_it->ignore_bn_limit <= -1)
+              {
+                if (!bidi_it->invalid_isolates)
+                  {
+                    if (bidi_it->invalid_levels)
+                      bidi_it->invalid_levels--;
+                    else if (!isolate_status && bidi_it->stack_idx >= 1)
+                      new_level = bidi_pop_embedding_level (bidi_it);
+                  }
+                bidi_it->resolved_level = new_level;
+              }
+            break;
           default:
             /* Nothing.  */
             break;