Make display lists reference counted objects.

Remove fz_free_display_list from the API; instead use fz_drop_display_list.

4 files changed, 47 insertions, 20 deletions

diff --git a/fitz/dev_list.c b/fitz/dev_list.c
index 5caf34fd..972c4ba5 100644
--- a/fitz/dev_list.c
+++ b/fitz/dev_list.c
@@ -52,6 +52,7 @@ struct fz_display_node_s
 
 struct fz_display_list_s
 {
+	fz_storable storable;
 	fz_display_node *first;
 	fz_display_node *last;
 	int len;
@@ -586,10 +587,29 @@ fz_new_list_device(fz_context *ctx, fz_display_list *list)
 	return dev;
 }
 
+static void
+fz_free_display_list(fz_context *ctx, fz_storable *list_)
+{
+	fz_display_list *list = (fz_display_list *)list_;
+	fz_display_node *node;
+
+	if (list == NULL)
+		return;
+	node = list->first;
+	while (node)
+	{
+		fz_display_node *next = node->next;
+		fz_free_display_node(ctx, node);
+		node = next;
+	}
+	fz_free(ctx, list);
+}
+
 fz_display_list *
 fz_new_display_list(fz_context *ctx)
 {
 	fz_display_list *list = fz_malloc_struct(ctx, fz_display_list);
+	FZ_INIT_STORABLE(list, 1, fz_free_display_list);
 	list->first = NULL;
 	list->last = NULL;
 	list->len = 0;
@@ -598,21 +618,16 @@ fz_new_display_list(fz_context *ctx)
 	return list;
 }
 
-void
-fz_free_display_list(fz_context *ctx, fz_display_list *list)
+fz_display_list *
+fz_keep_display_list(fz_context *ctx, fz_display_list *list)
 {
-	fz_display_node *node;
+	return (fz_display_list *)fz_keep_storable(ctx, &list->storable);
+}
 
-	if (list == NULL)
-		return;
-	node = list->first;
-	while (node)
-	{
-		fz_display_node *next = node->next;
-		fz_free_display_node(ctx, node);
-		node = next;
-	}
-	fz_free(ctx, list);
+void
+fz_drop_display_list(fz_context *ctx, fz_display_list *list)
+{
+	fz_drop_storable(ctx, &list->storable);
 }
 
 static fz_display_node *
diff --git a/fitz/fitz.h b/fitz/fitz.h
index 1dc12ff9..73bf8bcd 100644
--- a/fitz/fitz.h
+++ b/fitz/fitz.h
@@ -2380,7 +2380,7 @@ struct fz_cookie_s
 	Create a displaylist with fz_new_display_list, hand it over to
 	fz_new_list_device to have it populated, and later replay the
 	list (once or many times) by calling fz_run_display_list. When
-	the list is no longer needed free it with fz_free_display_list.
+	the list is no longer needed drop it with fz_drop_display_list.
 */
 typedef struct fz_display_list_s fz_display_list;
 
@@ -2434,14 +2434,19 @@ fz_device *fz_new_list_device(fz_context *ctx, fz_display_list *list);
 void fz_run_display_list(fz_display_list *list, fz_device *dev, const fz_matrix *ctm, const fz_rect *area, fz_cookie *cookie);
 
 /*
-	fz_free_display_list: Frees a display list.
+	fz_keep_display_list: Keep a reference to a display list.
 
-	list: Display list to be freed. Any objects put into the
-	display list by a list device will also be freed.
+	Does not throw exceptions.
+*/
+fz_display_list *fz_keep_display_list(fz_context *ctx, fz_display_list *list);
+
+/*
+	fz_drop_display_list: Drop a reference to a display list, freeing it
+	if the reference count reaches zero.
 
 	Does not throw exceptions.
 */
-void fz_free_display_list(fz_context *ctx, fz_display_list *list);
+void fz_drop_display_list(fz_context *ctx, fz_display_list *list);
 
 /*
 	Links
diff --git a/fitz/res_font.c b/fitz/res_font.c
index 3263f88c..db2ffe5d 100644
--- a/fitz/res_font.c
+++ b/fitz/res_font.c
@@ -103,7 +103,7 @@ fz_drop_font(fz_context *ctx, fz_font *font)
 			if (font->t3procs[i])
 				fz_drop_buffer(ctx, font->t3procs[i]);
 			if (font->t3lists[i])
-				fz_free_display_list(ctx, font->t3lists[i]);
+				fz_drop_display_list(ctx, font->t3lists[i]);
 		}
 		fz_free(ctx, font->t3procs);
 		fz_free(ctx, font->t3lists);
diff --git a/fitz/text_extract.c b/fitz/text_extract.c
index bf50e6a4..01a789fd 100644
--- a/fitz/text_extract.c
+++ b/fitz/text_extract.c
@@ -369,7 +369,12 @@ fz_new_text_sheet(fz_context *ctx)
 void
 fz_free_text_sheet(fz_context *ctx, fz_text_sheet *sheet)
 {
-	fz_text_style *style = sheet->style;
+	fz_text_style *style;
+	
+	if (sheet == NULL)
+		return;
+
+	style = sheet->style;
 	while (style)
 	{
 		fz_text_style *next = style->next;
@@ -478,6 +483,8 @@ void
 fz_free_text_page(fz_context *ctx, fz_text_page *page)
 {
 	fz_page_block *block;
+	if (page == NULL)
+		return;
 	for (block = page->blocks; block < page->blocks + page->len; block++)
 	{
 		switch (block->type)