Add buffer flags

New API:

	hb_buffer_flags_t

	HB_BUFFER_FLAGS_DEFAULT
	HB_BUFFER_FLAG_BOT
	HB_BUFFER_FLAG_EOT
	HB_BUFFER_FLAG_PRESERVE_DEFAULT_IGNORABLES

	hb_buffer_set_flags()
	hb_buffer_get_flags()

We use the BOT flag to decide whether to insert dottedcircle if the
first char in the buffer is a combining mark.

The PRESERVE_DEFAULT_IGNORABLES flag prevents removal of characters like
ZWNJ/ZWJ/...

1 files changed, 21 insertions, 19 deletions

diff --git a/src/hb-ot-shape-complex-arabic.cc b/src/hb-ot-shape-complex-arabic.cc
index cba79339..59c97167 100644
--- a/src/hb-ot-shape-complex-arabic.cc
+++ b/src/hb-ot-shape-complex-arabic.cc
@@ -250,17 +250,18 @@ arabic_joining (hb_buffer_t *buffer)
   HB_BUFFER_ALLOCATE_VAR (buffer, arabic_shaping_action);
 
   /* Check pre-context */
-  for (unsigned int i = 0; i < buffer->context_len[0]; i++)
-  {
-    unsigned int this_type = get_joining_type (buffer->context[0][i], buffer->unicode->general_category (buffer->context[0][i]));
+  if (!(buffer->flags & HB_BUFFER_FLAG_BOT))
+    for (unsigned int i = 0; i < buffer->context_len[0]; i++)
+    {
+      unsigned int this_type = get_joining_type (buffer->context[0][i], buffer->unicode->general_category (buffer->context[0][i]));
 
-    if (unlikely (this_type == JOINING_TYPE_T))
-      continue;
+      if (unlikely (this_type == JOINING_TYPE_T))
+	continue;
 
-    const arabic_state_table_entry *entry = &arabic_state_table[state][this_type];
-    state = entry->next_state;
-    break;
-  }
+      const arabic_state_table_entry *entry = &arabic_state_table[state][this_type];
+      state = entry->next_state;
+      break;
+    }
 
   for (unsigned int i = 0; i < count; i++)
   {
@@ -282,18 +283,19 @@ arabic_joining (hb_buffer_t *buffer)
     state = entry->next_state;
   }
 
-  for (unsigned int i = 0; i < buffer->context_len[1]; i++)
-  {
-    unsigned int this_type = get_joining_type (buffer->context[1][i], buffer->unicode->general_category (buffer->context[0][i]));
+  if (!(buffer->flags & HB_BUFFER_FLAG_EOT))
+    for (unsigned int i = 0; i < buffer->context_len[1]; i++)
+    {
+      unsigned int this_type = get_joining_type (buffer->context[1][i], buffer->unicode->general_category (buffer->context[0][i]));
 
-    if (unlikely (this_type == JOINING_TYPE_T))
-      continue;
+      if (unlikely (this_type == JOINING_TYPE_T))
+	continue;
 
-    const arabic_state_table_entry *entry = &arabic_state_table[state][this_type];
-    if (entry->prev_action != NONE && prev != (unsigned int) -1)
-      buffer->info[prev].arabic_shaping_action() = entry->prev_action;
-    break;
-  }
+      const arabic_state_table_entry *entry = &arabic_state_table[state][this_type];
+      if (entry->prev_action != NONE && prev != (unsigned int) -1)
+	buffer->info[prev].arabic_shaping_action() = entry->prev_action;
+      break;
+    }
 
 
   HB_BUFFER_DEALLOCATE_VAR (buffer, arabic_shaping_action);